Display and its manufacturing method

ABSTRACT

Disclosed is a display device comprising an optical waveguide plate  12  for introducing light  10  thereinto; an actuator substrate  18  provided opposingly to one plate surface of the optical waveguide plate  12  and arranged with actuator elements  14  of a number corresponding to a large number of pixels; a pixel structure  102  formed on each of the actuator elements  14  of the actuator substrate  18 ; and a crosspiece  70  formed at a portion other than the pixel structure  102  between the optical waveguide plate  12  and the actuator substrate  18 . Accordingly, it is easy to form a gap between the optical waveguide plate and the pixel structure. Further, the gap can be formed uniformly for all of the pixels.

TECHNICAL FIELD

The present invention relates to a display device which consumes lesselectric power, and which has large screen brightness. In particular,the present invention relates to improvement in the display device fordisplaying a picture image corresponding to an image signal on anoptical waveguide plate by controlling leakage light at a predeterminedposition on the optical waveguide plate by controlling the displacementaction of an actuator element in a direction to make contact orseparation with respect to the optical waveguide plate in accordancewith the attribute of the image signal to be inputted. The presentinvention also relates to a method for producing the display device.

BACKGROUND ART

Those hitherto known as the display device include, for example, cathoderay tubes (CRT) and liquid crystal display devices.

Those known as the cathode ray tube include, for example, ordinarytelevision receivers and monitor units for computers. Although thecathode ray tube has a bright screen, it consumes a large amount ofelectric power.

Further, the cathode ray tube involves a problem that the depth of theentire display device is large as compared with the size of the screen.

On the other hand, the liquid crystal display device is advantageous inthat the entire device can be miniaturized, and the display deviceconsumes a small amount of electric power. However, the liquid crystaldisplay device involves problems that it is inferior in brightness ofthe screen, and the field angle of the screen is narrow.

In the case of the cathode ray tube and the liquid crystal displaydevice, it is necessary for a color screen to use a number of pixelswhich is three times a number of pixels used in a black-and-whitescreen. For this reason, other problems occur in that the device itselfis complicated, a great deal of electric power is consumed, and it isinevitable to cause the increase in cost.

In order to solve the problems described above, the present applicanthas suggested a novel display device (see, for example, JapaneseLaid-Open Patent Publication No. 7-287176). As shown in FIG. 63, thisdisplay device includes actuator elements 400 arranged for respectivepixels. Each of the actuator elements 400 comprises a main actuatorelement 408 including a piezoelectric/electrostrictive layer 402 and anupper electrode 404 and a lower electrode 406 formed on upper and lowersurfaces of the piezoelectric/electrostrictive layer 402 respectively,and an actuator substrate 414 including a vibrating section 410 and afixed section 412 disposed under the main actuator element 408. Thelower electrode 406 of the main actuator element 408 contacts with thevibrating section 410. The main actuator element 408 is supported by thevibrating section 410.

The actuator substrate 414 is composed of ceramics in which thevibrating section 410 and the fixed section 412 are integrated into oneunit. A recess 416 is formed in the actuator substrate 414 so that thevibrating section 410 is thin-walled.

A displacement-transmitting section 420 for obtaining a predeterminedsize of contact area with respect to an optical waveguide plate 418 isconnected to the upper electrode 404 of the main actuator element 408.In the illustrative display device shown in FIG. 63, thedisplacement-transmitting section 420 is arranged such that it islocated closely near to the optical waveguide plate 418 in the OFFselection state or the NO selection state in which the actuator element400 stands still, while it contacts with the optical waveguide plate 418in the ON selection state at a distance of not more than the wavelengthof the light.

The light 422 is introduced, for example, from a lateral end of theoptical waveguide plate 418. In this arrangement, all of the light 422is totally reflected at the inside of the optical waveguide plate 418without being transmitted through front and back surfaces thereof bycontrolling the magnitude of the refractive index of the opticalwaveguide plate 418. In this state, a voltage signal corresponding to anattribute of an image signal is selectively applied to the actuatorelement 400 by the aid of the upper electrode 404 and the lowerelectrode 406 so that the actuator element 400 is allowed to make avariety of displacement actions in conformity with the ON selection, theOFF selection, and the NO selection. Thus, the displacement-transmittingsection 420 is controlled for its contact and separation with respect tothe optical waveguide plate 418. Accordingly, the scattered light(leakage light) 424 is controlled at a predetermined portion of theoptical waveguide plate 418, and a picture image corresponding to theimage signal is displayed on the optical waveguide plate 418.

When a color picture is displayed by using the display device, thefollowing operation is performed. That is, for example, light sourcesfor three primary colors are switched to control the light emission timefor three primary colors while synchronizing the contact time betweenthe optical waveguide plate and the displacement-transmitting plate withthe period of color development. Alternatively, the contact time betweenthe optical waveguide plate and the displacement-transmitting plate iscontrolled, while synchronizing the light emission time for threeprimary colors with the color development period.

Therefore, the illustrative display device suggested by the presentapplicant is advantageous in that it is unnecessary to increase thenumber of pixels as compared with the black-and-white screen, even whenthe display device is applied to the color display system.

An object of the present invention is to provide a display device and amethod for producing the same to exhibit the following effects, byimproving the arrangement of the illustrative display device suggestedby the present applicant.

(1) The clearance (gap) can be easily formed between the opticalwaveguide plate and the pixel structure, and the gap can be formeduniformly for all of the pixels.

(2) The size of the gap can be easily controlled.

(3) The adhesion of the pixel structure to the optical waveguide platecan be avoided, and it is possible to effectively realize a highresponse speed.

(4) The contact surface of the pixel structure (contact surface withrespect to the optical waveguide plate) can be formed to be smooth sothat the light is efficiently introduced into the pixel structure whenthe predetermined pixel structure makes contact with the opticalwaveguide plate.

(5) It is possible to ensure the response speed of the pixel.

(6) It is possible to obtain the uniform brightness for all of thepixels.

(7) It is possible to improve the brightness of the pixel.

DISCLOSURE OF THE INVENTION

According to the present invention, there is provided a display devicecomprising an optical waveguide plate for introducing light thereinto;an actuator substrate provided opposingly to one plate surface of theoptical waveguide plate and arranged with actuator elements of a numbercorresponding to a large number of pixels; a pixel structure formed oneach of the actuator elements of the actuator substrate; and acrosspiece formed at a portion other than the pixel structure betweenthe optical waveguide plate and the actuator substrate (invention asdefined in claim 1).

According to the present invention, all of the light, which isintroduced, for example, from a lateral end of the optical waveguideplate, is totally reflected at the inside of the optical waveguide platewithout being transmitted through front and back surfaces thereof bycontrolling the magnitude of the refractive index of the opticalwaveguide plate. In this state, when the displacement-transmittingsection approaches the optical waveguide plate in accordance with thedisplacement action of the actuator section, the light, which has beensubjected to total reflection, is reflected by the pixel structure, andit behaves as scattered light. A part of the scattered light isreflected again in the optical waveguide plate. However, almost all ofthe scattered light is transmitted through the front surface of theoptical waveguide plate without being reflected by the optical waveguideplate.

The arrangement described above is illustrative of the case in which thepixel structure is displaced in the direction to make approach to theoptical waveguide plate in accordance with the displacement action ofthe actuator element. Alternatively, the present invention is alsoapplicable to the case in which the pixel structure is displaced in thedirection to make separation from the optical waveguide plate inaccordance with the displacement action of the actuator element.

As described above, the presence or absence of light emission (leakagelight) at the front surface of the optical waveguide plate can becontrolled in accordance with the approach and separation of the pixelstructure disposed at the back of the optical waveguide plate, withrespect to the optical waveguide plate. In this arrangement, forexample, one unit for allowing the pixel structure to make displacementaction in the direction to make the approach or separation with respectto the optical waveguide plate may be regarded as one pixel. A pictureimage (for example, characters and graphics) corresponding to the imagesignal can be displayed on the front surface of the optical waveguideplate in the same manner as in the cathode ray tube and the liquidcrystal display device, by arranging a large number of the pixels in amatrix form, and controlling the displacement action of each of thepixels in accordance with the attribute of the inputted image signal.

When the display device of the present invention is applied to the colordisplay system, the following arrangement may be adopted, for example,in relation to the color scheme of the color layers (for example, threeprimary color filters, complementary color filters, or color scatteringelements) disposed for the pixel structures. That is, for example, onepixel may be constructed by three pixel structures adjacent to oneanother (RGB arrangement) or by four pixel structures adjacent to oneanother (for example, checked arrangement).

It is noted that the display device according to the present inventioncomprises the crosspiece formed at the portions other than the pixelstructures between the optical waveguide plate and the actuatorsubstrate.

If the optical waveguide plate and the actuator substrate are fixed byusing only the circumferential edge of the screen without providing anycrosspiece, the vibration occurs in the actuator substrate due to themovement of the actuator element. Every time when the vibration occurs,the displacement standard is changed. As a result, the ON/OFF operationof the pixel does not correspond to the displacement of the actuatorelement in some cases.

However, in the present invention, the crosspiece is provided asdescribed above. Therefore, even when a certain actuator element makesdisplacement action, the vibration thereof is absorbed by thecrosspiece. Accordingly, no inconvenience occurs, which would otherwiseoccur such that the displacement standard is changed.

The support effected for the optical waveguide plate by the plurality ofcrosspieces formed around the pixel structure makes it easy to obtain auniform gap between the pixel structure and the optical waveguide platefor all of the pixels. Further, the size of the gap can be easilycontrolled by arbitrarily changing the height of the crosspiece. As aresult, it is possible to obtain a uniform brightness for all of thepixels.

In the arrangement described above, it is also preferable that theactuator element includes a shape-retaining layer, an operating sectionhaving at least a pair of electrodes formed on the shape-retaining layera vibrating section for supporting the operating section and a fixedsection for supporting the vibrating section in a vibrating manner(invention as defined in claim 2).

In the display device constructed as described above, the term “actuatorsection including the shape-retaining layer” refers to an actuatorelement which has at least two or more displacement states at anidentical voltage level.

The actuator element having the shape-retaining layer has the followingfeatures.

(1) The threshold characteristic concerning the change from the OFFstate to the ON state is steep as compared with the case in which noshape-retaining layer exists. Accordingly, it is possible to narrow thedeflection width of the voltage, and it is possible to mitigate the loadon the circuit.

(2) The difference between the ON state and the OFF state is distinct,resulting in improvement in contrast.

(3) The dispersion of threshold value is decreased, and an enough marginis provided for the voltage setting range. It is desirable to use, asthe actuator element, an actuator element which makes, for example,upward displacement (giving the separated state upon no voltage load andgiving the contact state upon voltage application) because of easinessof control. Especially, it is desirable to use an actuator elementhaving a structure including a pair of electrodes on its surface.

(4) It is preferable to use, for example, apiezoelectric/electrostrictive layer and an anti-ferroelectric layer asthe shape-retaining layer.

In the display device constructed as described above, it is alsopreferable that the crosspiece is secured to the optical waveguide plate(invention as defined in claim 3).

Alternatively, it is also preferable that a gap-forming layer isprovided between the optical waveguide plate and the crosspiece(invention as defined in claim 4). When the gap-forming layer isprovided, it is easier to obtain a uniform gap between the pixelstructure and the optical waveguide plate for all of the pixels. Thesize of the gap can be easily controlled as well.

The constitutive material for the gap-forming layer includes, forexample, metal films, films containing carbon black, black pigment, orblack dye, and transparent films having low light-scattering property.Accordingly, the gap-forming layer is allowed to simultaneously have thefunction of black matrix. Especially, when a metal film composed of, forexample, Cr, Al, Ni, or Ag is used as the gap-forming layer, theattenuation and the scattering of the light transmitted through theoptical waveguide plate can be suppressed, because a small amount oflight is absorbed thereby. Therefore, such a metal film is usedespecially preferably.

When a film containing carbon black, black pigment, or black dye is usedas the gap-forming layer, then the light-absorbing performance isexcellent, and it is possible to improve the contrast. When atransparent film having a poor light-scattering property is used as thegap-forming layer, then the light scattering can be suppressed, and thecontrast can be enhanced by combining the film with an adhesive havingan excellent light-absorbing property (or an adhesive having alight-absorbing property enhanced by adding black dye or black pigment).

The size of the gap-forming layer is set as follows, for example, asexemplified by the case in which the actuator element is displaced to beconvex toward the optical waveguide plate. That is, the small limit(minimum value) of the gap amount is set to be such a degree that theleakage of light caused by the evanescent effect upon the OFF state ofthe pixel can be neglected. The large limit (maximum value) of the gapamount is set to be within a range in which the pixel structure can makecontact with the optical waveguide plate in accordance with thedisplacement of the actuator element. Therefore, the thickness of thegap-forming layer is adjusted so that the gap amount is set to be withinthe range described above. However, the difference in height between thepixel structure and the crosspiece is controllable depending on variousembodiments of the display device. The thickness of the gap-forminglayer may be optimized in accordance therewith.

In the display device constructed as described above, it is alsopreferable that the crosspiece is formed at portions around four cornersof each of the pixel structure (invention as defined in claim 5). Theterm “portions around the four corners of the pixel structure” includes,for example, positions corresponding to the respective corners when thepixel structure has, for example, a rectangular or elliptic planarconfiguration. The term refers to a form in which one crosspiece issheared by the adjoining pixel structure. In this arrangement, fourcrosspieces are formed for one unit of the pixel structure. Accordingly,the vibration, which is caused by the displacement action of a certainactuator element, is effectively absorbed. As a result, the displacementaction of the other actuator elements is scarcely and hardly affectedthereby. As a result, the correspondence is well improved between thedisplacement and the ON operation/OFF operation for all of the pixels.It is possible to faithfully display a picture image corresponding tothe inputted image signal. Further, the actuator substrate and theoptical waveguide plate are tightly secured to one another.

It is also preferable that the crosspiece is formed to have a window forsurrounding at least one pixel structure (invention as defined in claim6). A representative example is constructed, for example, such that thecrosspiece itself is formed to have a plate-shaped configuration, andthe window (opening) is formed at a position corresponding to the pixelstructure. Accordingly, an arrangement is achieved, in which all sidesurfaces of the pixel structure are surrounded by the crosspiece. Theactuator substrate and the optical waveguide plate are secured to oneanother more tightly. Further, the vibration caused by the displacementaction of a certain actuator element does not affect the displacementaction of the other actuator elements at all.

It is also preferable that the crosspiece is constructed such that itincludes a stripe-shaped opening which extends along a direction of anarray of the pixel structures and which surrounds the array of the pixelstructures (invention as defined in claim 7). Alternatively, it is alsopreferable that the crosspiece is formed to have a line-shapedconfiguration which extends along a direction of an array of the pixelstructures (invention as defined in claim 8).

It is also preferable that the crosspiece is formed integrally with theactuator substrate (invention as defined in claim 9). In thisarrangement, it is possible to improve the mechanical strength of theportion at which the crosspiece is formed. Accordingly, the rigidity ofthe actuator substrate is increased. As a result, the actuator element,which is formed on the actuator substrate, can be protected with thecrosspiece, for example, when the actuator substrate is carried orstored. The step of hardening the crosspiece can be omitted, as comparedwith the case in which the crosspiece is formed separately. Thus, it ispossible to reduce the number of production steps.

It is also preferable that the crosspiece is constructed by a wiremember which extends along a direction of an array of the pixelstructures (invention as defined in claim 10).

In the display device constructed as described above, it is alsopreferable that a recess is formed on a surface of the pixel structure(invention as defined in claim 11).

In this arrangement, the number of recesses to be formed or the size ofthe recess is defined depending on the area of the pixel structureopposing to the optical waveguide plate. By doing so, it is possible toprovide a substantially identical contact area with respect to theoptical waveguide plate concerning the respective pixel structures.Thus, it is possible to obtain a uniform brightness for all of thepixels. The presence of the recess mitigate the tight contact betweenthe pixel structure and the optical waveguide plate. Thus, the pixelstructure is smoothly separated from the optical waveguide plate. As aresult, the pixel-structure can be prevented from adhesion to theoptical waveguide plate. Thus, it is possible to effectively realize ahigh response speed.

In the display device constructed as described above, it is alsopreferable that a step is formed on a surface of the pixel structure(invention as defined in claim 12). In this arrangement, the provisionof the step on the pixel structure makes it possible to obtain aconstant area of the portion of the pixel structure to make contact withthe optical waveguide plate for all of the pixels. It is possible toobtain a uniform brightness for all of the pixels. The presence of thestep mitigate the tight contact between the pixel structure and theoptical waveguide plate. Accordingly, the pixel structure can beprevented from adhesion to the optical waveguide plate, and thus it ispossible to effectively realize a high response speed.

In the display device constructed as described above, it is also,preferable that a surface of the pixel structure has a concaveconfiguration (invention as defined in claim 13). When the actuatorelement makes displacement, the central portion of the pixel structuretends to have the largest displacement amount. Therefore, when thesurface of the pixel structure is allowed to have the concaveconfiguration so that the central portion of the pixel structure isconcave, the surface of the pixel structure is approximately flat whenthe actuator element makes displacement to allow the pixel structure tomake contact with the optical waveguide plate. Accordingly, it ispossible to increase the contact area of the pixel structure withrespect to the optical waveguide plate.

When the depth of the concave curve is increased, a state is given, inwhich the central portion of the pixel structure does not arrive at theoptical waveguide plate when the pixel structure makes contact with theoptical waveguide plate, giving a state in which a recess is formed onthe surface of the pixel structure in a simulated manner. Accordingly,the tight contact between the pixel structure and the optical waveguideplate is mitigated. Thus, the pixel structure is smoothly separated fromthe optical waveguide plate. As a result, the pixel structure can beprevented from adhesion to the optical waveguide plate, and it ispossible to effectively realize a high response speed.

The arrangement in which the recess is formed on the surface of thepixel structure, the arrangement in which the step is formed on thesurface of the pixel structure, and the arrangement in which the surfaceof the pixel structure has the concave configuration may be realizedsingly respectively, or they may be arbitrarily combined with eachother. The combination of them makes it possible to obtain thesynergistic effect on the basis of the respective arrangements.

According to another aspect of the present invention, there is provideda method for producing a display device, comprising a crosspiece-formingstep of forming a plurality of crosspieces at portions other thanactuator elements, of an actuator substrate arranged with the actuatorelements corresponding to a large number of pixels; a pixel-forming stepof forming pixel structures on the respective actuator elements on theactuator substrate; and a pressurizing step of laminating andpressurizing an optical waveguide plate in a state in which at least thepixel structures are not hardened, and then hardening at least the pixelstructures (invention as defined in claim 14).

It is noted that the state in which the pixel structures are nothardened includes a state in which all of stacked films are nothardened, and a state in which a part of films are not hardened, whenthe pixel structure is constructed by a plurality of stacked films(multiple layered structure).

In this aspect, it is possible to obtain the precise positionalalignment for the pixel structure and the crosspiece with respect to theactuator substrate, as well as it is possible to obtain the strongadhesive force. Further, the cleanness of the optical waveguide platecan be highly maintained, because the optical waveguide plate is finallylaminated.

According to still another aspect of the present invention, there isprovided a method for producing a display device, comprising acrosspiece-forming step of forming a plurality of crosspieces atportions other than portions corresponding to a large number of actuatorelements, of an optical waveguide plate; a pixel-forming step of formingpixel structures at portions corresponding to the large number ofpixels, of the optical waveguide plate; and a pressurizing step oflaminating an actuator substrate arranged with actuator elements of anumber corresponding to the large number of pixels, on the crosspiecesand the pixel structures, and pressurizing the optical waveguide plateand the actuator substrate in directions to make approach to one another(invention as defined in claim 15).

In this method, the pixel structures and the crosspieces are formed onthe optical waveguide plate, and the actuator substrate is laminatedthereon. This method is advantageous in that the area of the pixel(contact area with respect to the optical waveguide plate) is easilydefined, because the pixel structures are directly formed on the opticalwaveguide plate. Further, it is easy, to obtain a uniform brightness forall of the pixels.

According to still another aspect of the present invention, there isprovided a method for producing a display device, comprising acrosspiece-forming step of forming a plurality of crosspieces atportions other than actuator elements, of an actuator substrate arrangedwith the actuator elements corresponding to a large number of pixels; apixel-forming step of forming pixel structures at portions correspondingto the large number of pixels, of an optical waveguide plate; and apressurizing step of laminating a surface of the actuator substrateformed with the crosspieces and a surface of the optical waveguide plateformed with the pixel structures with each other, and pressuring theoptical waveguide plate and the actuator substrate in directions to makeapproach to one another (invention as defined in claim 16).

In this method, the pixel structures are formed on the optical waveguideplate, and the crosspieces are formed on the actuator substrate. Afterthat, the optical waveguide plate and the actuator substrate arelaminated with each other.

In this aspect, the formation of the pixel structures and the formationof the crosspieces can be performed in the steps which are independentfrom each other. Accordingly, the range of material selection is widenedconcerning the pixel structure and the crosspiece. Thus, it is possibleto reduce the production cost and the number of production steps.Further, the size of the pixel structure can be made uniform, becausethe pixel structures are formed on the optical waveguide plate which hashigh flatness.

According to still another aspect of the present invention, there isprovided a method for producing a display device, comprising acrosspiece-forming step of forming a plurality of crosspieces atportions other than portions corresponding to a large number of actuatorelements, of an optical waveguide plate; a pixel-forming step of formingpixel structures on respective actuator elements of an actuatorsubstrate arranged with the actuator elements of a number correspondingto the large number of pixels; and a pressurizing step of laminating asurface of the actuator substrate formed with the pixel structures and asurface of the optical waveguide plate formed with the crosspieces witheach other, and pressuring the optical waveguide plate and the actuatorsubstrate in directions to make approach to one another (invention asdefined in claim 17).

In this method, the crosspieces are formed on the optical waveguideplate, and the pixel structures are formed on the actuator substrate.After that, the optical waveguide plate and the actuator substrate arelaminated with each other.

Also in this aspect, the formation of the pixel structures and theformation of the crosspieces can be performed in the steps which areindependent from each other. Accordingly, the range of materialselection is widened concerning the pixel structure and the crosspiece.Thus, it is possible to reduce the production cost and the number ofproduction steps. Further, the height of the crosspiece can be madestrictly uniform, because the crosspieces are formed on the opticalwaveguide plate which has high flatness. Furthermore, for example, noobstacle (for example, the crosspiece) exists upon the formation of thepixel structure. Therefore, it is possible to accurately, form the pixelstructure.

According to still another aspect of the present invention, there isprovided a method for producing a display device, comprising apixel-forming step of forming pixel structures on respective actuatorelements of an actuator substrate arranged with the actuator elements ofa number corresponding to a large number of pixels and integrally havinga plurality of crosspieces at portions other than the actuator elements;and a pressurizing step of laminating and pressurizing an opticalwaveguide plate in a state in which at least the pixel structures arenot hardened, and then hardening at least the pixel structures(invention as defined in claim 18).

In this method, the pixel structures are formed on the actuatorsubstrate which is previously provided with the crosspieces in theintegrated manner. After that, the optical waveguide plate is laminatedand pressurized.

In this aspect, the actuator substrate, which previously has thecrosspieces in the integrated manner, it used as the actuator substrate.Therefore, the portion of the crosspiece has high mechanical strength.Accordingly, the rigidity of the actuator substrate is increased. As aresult, for example, when the actuator substrate is carried or stored,the crosspieces can be used to protect the actuator elements formed onthe actuator substrate. The step of hardening the crosspieces can beomitted, as compared with the case in which the crosspieces areseparately formed. Thus, it is possible to reduce the number ofproduction steps.

In the production methods described above, the optical waveguide plateis laminated and pressurized in the state in which at least the pixelstructures are not hardened. Accordingly, the optical waveguide platepresses the crosspieces and the pixel structures toward the actuatorsubstrate during the pressurizing process. Thus, a substantiallyidentical surface is formed by the upper surface of the pixel structureand the upper surface of the crosspiece when at least the pixelstructure is hardened.

In this aspect, a material, with which the pixel structure is contractedupon the hardening of the pixel structure, is used as the constitutivematerial for the pixel structure. By doing so, it is possible to form agap between the optical waveguide plate and the pixel structure duringthe hardening process for the crosspiece and the pixel structure.

Other methods are available to form the gap. That is, for example, whenthe optical waveguide plate is laminated and pressurized, the pixelstructure is heated and expanded, or the actuator element is displacedto allow the pixel structure to make contact with the optical waveguideplate. It is also possible to adopt a combination of the methods asdescribed above. After that, when the crosspiece and the pixel structureare hardened, a constant gap is formed between the pixel structure andthe optical waveguide plate in accordance with the contraction of thepixel structure or the displacement reset (restoration) of the actuatorelement.

Another arrangement is available, in which the pixel structure contactswith the optical waveguide plate in the natural state. This arrangementis applicable to a case in which the displacement action of the actuatorelement resides in the displacement of the pixel structure in adirection to make separation from the optical waveguide plate.

In the production methods described above, it is preferable that thecrosspiece is hardened, or the crosspiece is partially hardened when theoptical waveguide plate is laminated. In this arrangement, thecrosspiece acts as a spacer to define the distance between the actuatorsubstrate and the optical waveguide plate.

According to still another aspect of the present invention, there isprovided a method for producing a display device, comprising acrosspiece-forming step of forming a plurality of crosspieces atportions other than actuator elements, of an actuator substrate arrangedwith the actuator elements of a number corresponding to a large numberof pixels; a pixel-forming step of forming pixel structures on therespective actuator elements of the actuator substrate; a firstlaminating step of laminating a plate member in a state in which atleast the pixel structures are not hardened; a pressurizing step ofpressurizing the actuator substrate and the plate member in directionsto make approach to one another, and then hardening at least the pixelstructures; and a second laminating step of removing the plate member,and then laminating an optical waveguide plate at least on thecrosspieces (invention as defined in claim 19).

In this method, the plate member is once laminated on the actuatorsubstrate which is formed with the pixel structures and the crosspiecesto give a substantially identical surface for the respective uppersurfaces of the pixel structures and the crosspieces. After that, theplate member is removed, and the optical waveguide plate is laminated.

In this aspect, it is possible to obtain the precise positionalalignment and the strong adhesive force for the pixel structure and thecrosspiece with respect to the actuator substrate.

The crosspieces, which have been formed on the actuator substrate, serveas the spacer when the plate member is laminated and pressurized on theactuator substrate. Thus, the distance is defined between the actuatorsubstrate and the plate member. If the crosspieces are hardened, or ifthe crosspieces are partially hardened when the optical waveguide plateis laminated, the distance defined as described above corresponds to thedistance between the actuator substrate and the optical waveguide plate.

When a smooth plate member is used as the plate member, a smooth surfaceequivalent to the surface of the plate member is formed on the surfaceof the pixel structure. The excellent smoothness is useful to improvethe brightness when the pixels cause light emission. It is preferablethat a releasing agent is applied to the plate member.

In the method described above, it is also preferable that only thecrosspieces are subjected to figuring (crosspiece formation→figuringhardening) after the formation of the crosspieces on the actuatorsubstrate. When the plate member is laminated, it is possible tocompensate the portion at which the crosspiece does not abut against theplate member, and it is possible to define the height of the crosspiecewhile absorbing the waviness of the actuator substrate. Further, whenthe pixel structure is formed, the pixel structure is simultaneouslyformed on the crosspiece as well to perform the figuring. Also in thisarrangement, it is possible to define the height of the crosspiece whileabsorbing the waviness of the actuator substrate.

According to still another aspect of the present invention, there isprovided a method for producing a display device, comprisingcrosspiece-forming step of forming a plurality of crosspieces atportions other than portions corresponding to a large number of pixels,of a plate member; a pixel-forming step of forming pixel structures atthe portions corresponding to the large number of pixels, of the platemember; a first laminating step of laminating an actuator substratearranged with actuator elements of a number corresponding to the largenumber of pixels on the crosspieces and the pixel structures; apressurizing step of pressurizing the plate member and the actuatorsubstrate in directions to make approach, to one another; and a secondlaminating step of removing the plate member to transfer the crosspiecesand the pixel structures to the actuator substrate, and then laminatingan optical waveguide plate on at least the crosspieces (invention asdefined in claim 20).

In this method, the pixel structures and the crosspieces are formed onthe plate member. After hardening them respectively, or withouthardening them, the actuator substrate is laminated. Subsequently, theplate member is removed, and the optical waveguide plate is laminated.

In this aspect, for example, it is preferable that a releasing agent isapplied to the plate member before the crosspieces and the pixelstructures are formed on the plate member. By doing so, it is possibleto smoothly transfer the pixel structures and the crosspieces to theactuator substrate.

In the present invention, when the actuator substrate is laminated andpressurized on the plate member formed with the crosspieces and thepixel structures, the crosspieces, which have been formed on the platemember, serve as the spacer to define the distance between the actuatorsubstrate and the plate member. When the crosspieces are hardened orpartially hardened upon the formation of the crosspieces on the platemember, the defined distance corresponds to the distance between theactuator substrate and the optical, waveguide plate.

According to still another aspect of the present invention, there isprovided a method for producing a display device, comprising acrosspiece-forming step of forming a plurality of crosspieces atportions other than actuator elements, of an actuator substrate arrangedwith the actuator elements of a number corresponding to a large numberof pixels; a pixel-forming step of forming pixel structures at portionscorresponding to the large number of pixels, of a plate member; a firstlaminating step of laminating a surface of the actuator substrate formedwith the crosspieces and a surface of the plate member formed with thepixel structures with each other; a pressurizing step of pressurizingthe plate member and the actuator substrate in directions to makeapproach to one another; and a second laminating step of removing theplate member to transfer the pixel structures to the actuator substrate,and then laminating an optical waveguide plate on at least thecrosspieces (invention as defined in claim 21).

In this method, the crosspieces are formed on the actuator substrate,and the pixel structures are formed on the plate member. The actuatorsubstrate and the plate member are laminated with each other. Afterthat, the plate member is removed, and the optical waveguide plate islaminated.

In this aspect, the formation of the pixel structures and the formationof the crosspieces can be performed in the independent stepsrespectively. Accordingly, the range of material selection is widenedconcerning the pixel structure and the crosspiece. Thus, it is possibleto reduce the production cost and the number of production steps.Further, the size of the pixel structure can be made uniform, becausethe pixel structures are formed on the plate member which has highflatness.

According to still another aspect of the present invention, there isprovided a method for producing a display device, comprising apixel-forming step of forming pixel structures on respective actuatorelements of an actuator substrate arranged with the actuator elements ofa number corresponding to a large number of pixels; a crosspiece-formingstep of forming a plurality of crosspieces at portions other thanportions corresponding to the large number of pixels, of a plate member;a first laminating step of laminating a surface of the actuatorsubstrate formed with the pixel structures and a surface of the platemember formed with the crosspieces with each other; a pressurizing stepof pressurizing the plate member and the actuator substrate indirections to make approach to one another; and a second laminating stepof removing the plate member to transfer the crosspieces to the actuatorsubstrate, and then laminating an optical waveguide plate on at leastthe crosspieces (invention as defined in claim 22).

In this method, the pixel structures are formed on the actuatorsubstrate, and the crosspieces are formed on the plate member. Theactuator substrate and the plate member are laminated with each other.After that, the plate member is removed, and the optical waveguide plateis laminated.

Also in this aspect, the formation of the pixel structures and theformation of the crosspieces can be performed in the independent stepsrespectively. Accordingly, the range of material selection is widenedconcerning the pixel structure and the crosspiece. Thus, it is possibleto reduce the production cost and the number of production steps.Further, the height of the crosspiece can be made strictly uniform,because the crosspieces are formed on the plate member which has highflatness. Furthermore, no obstacle (for example, the crosspiece) existsupon the formation of the pixel structure. Therefore, it is possible toaccurately form the pixel structure.

According to still another aspect of the present invention, there isprovided a method for producing a display device, comprising apixel-forming step of forming pixel structures on respective actuatorelements of an actuator substrate arranged with the actuator elements ofa number corresponding to a large number of pixels and integrally havinga plurality of crosspieces at portions other than the actuator elements;a first laminating step of laminating a plate member in a state in whichat least the pixel structures are not hardened; a pressurizing step ofpressurizing the actuator substrate and the plate member in directionsto make approach to one another, and then hardening at least the pixelstructures; and a second laminating step of removing the plate member,and then laminating an optical waveguide plate on at least thecrosspieces (invention as defined in claim 23).

In this method, the pixel structures are formed on the actuatorsubstrate which integrally has the crosspieces. Subsequently, the platemember is laminated on the actuator substrate. After that, the platemember is removed, and the optical waveguide plate is laminated.

In this aspect, the mechanical strength of the portion of the crosspieceis high, because the actuator substrate previously having thecrosspieces in the integrated manner is used as the actuator substrate.Accordingly, the rigidity of the actuator substrate is increased. As aresult, the actuator element, which is formed on the actuator substrate,can be protected with the crosspiece, for example, when the actuatorsubstrate is carried or stored. The step of hardening the crosspiece canbe omitted, as compared with the case in which the crosspiece isseparately formed. Thus, it is possible to reduce the number ofproduction steps.

According to still another aspect of the present invention, there isprovided a method for producing a display device, comprising apixel-forming step of forming pixel structures on respective actuatorelements of an actuator substrate arranged with the actuator elements ofa number corresponding to a large number of pixels; a first laminatingstep of using a jig including, on one surface of a plate member, a largenumber of size-defining members formed to have substantially the sameheight as, that of crosspieces to be formed on the actuator substrate tolaminate a surface of the jig formed with the size-defining members anda surface of the actuator substrate formed with the pixel structureswith each other; a pressurizing step of pressurizing the jig and theactuator substrate in directions to make approach to one another; acrosspiece-forming step of removing the jig, and then forming theplurality of crosspieces at portions other than the actuator sections,of the actuator substrate; and a second laminating step of laminating anoptical waveguide plate on at least the crosspieces on the actuatorsubstrate (invention as defined in claim 24).

In this method, the pixel structures are formed on the actuatorsubstrate. Subsequently, the jig including the large number ofsize-defining members formed on the plate member and the actuatorsubstrate are laminated and pressurized, and thus the size of the pixelstructures is defined. After that, the jig is removed, the crosspiecesare formed on the actuator substrate, and then the optical waveguideplate is laminated.

In this aspect, for example, when the jig is constructed by a memberhaving rigidity such as metal, the waviness of the actuator substrateformed with the pixel structures can be reduced by laminating andpressurizing the jig and the actuator substrate. The crosspieces can beformed highly accurately in the crosspiece-forming step performedthereafter.

According to still another aspect of the present invention, there isprovided a method for producing a display device, comprising apixel-forming step of forming pixel structures on respective actuatorelements of an actuator substrate arranged with the actuator elements ofa number corresponding to a large number of pixels: a first laminatingstep of using a jig including, on one surface of a plate member, a largenumber of size-defining members formed to have substantially the sameheight as that of crosspieces to be formed on the actuator substrate tolaminate a surface of the jig formed with the size-defining members anda surface of the actuator substrate formed with the pixel structureswith each other; a pressurizing step of pressurizing the jig and theactuator substrate in directions to make approach to one another; acrosspiece-forming forming step of removing the jig, and then formingthe plurality of crosspieces at portions other than portionscorresponding to the large number of pixels, of an optical waveguideplate; and a second laminating step of laminating a surface of theactuator substrate formed with the pixel structures and a surface of theoptical waveguide plate formed with the crosspieces with each other(invention as defined in claim 25).

In this method, the pixel structures are formed on the actuatorsubstrate. Subsequently, the jig including the plate member providedwith the large number of size-defining members and the actuatorsubstrate are laminated with each other to pressurize them. Thus, thesize of the pixel structures is defined. After the jig is removed, thecrosspieces are formed on the optical waveguide plate, and the opticalwaveguide plate and the actuator substrate are laminated with eachother.

Also in this aspect, for example, when the jig is constructed by amember having rigidity such as metal, the waviness of the actuatorsubstrate formed with the pixel structures can be reduced by laminatingand pressurizing the jig and the actuator substrate. The opticalwaveguide plate can be laminated highly accurately thereafter. Further,the height of the crosspiece can be made strictly uniform, because thecrosspieces are formed on the optical waveguide plate which has highflatness.

According to still another aspect of the present invention, there isprovided a method for producing a display device, comprising apixel-forming step of forming pixel structures on respective actuatorelements of an actuator substrate arranged with the actuator elements ofa number corresponding to a large number of pixels; a crosspiece-formingstep of using a jig including, on one surface of a plate member, a largenumber of size-defining members formed to have substantially the sameheight as that of crosspieces to be formed on the actuator substrate toform the plurality of crosspieces at portions formed with nosize-defining member, of a surface of the jig formed with thesize-defining members, the portions being other than portionscorresponding to the large number of pixels; a first laminating step oflaminating the surface of the jig formed with the size-defining membersand the crosspieces and a surface of the actuator substrate formed withthe pixel structures with each other; a pressurizing step ofpressurizing the jig and the actuator substrate in directions to makeapproach to one another; and a second laminating step of removing thejig to transfer the crosspieces to the actuator substrate, and thenlaminating an optical waveguide plate on at least the crosspieces on theactuator substrate (invention as defined in claim 26).

In this method, the pixel structures are formed on the actuatorsubstrate, and the crosspieces are formed on the jig including the platemember provided with the large number of size-defining members. Theactuator substrate and the jig are laminated with each other topressurize them. Thus, the size of the pixel structures is defined.After that, the jig is removed, the crosspieces are transferred to theactuator substrate, and the optical waveguide plate is laminated.

Also in this aspect, for example, when the jig is constructed by amember having rigidity such as metal, the waviness of the actuatorsubstrate formed with the pixel structures can be reduced by laminatingand pressurizing the jig and the actuator substrate. The crosspieces andthe pixel structures can be formed highly accurately.

According to still another aspect of the present invention, there isprovided a method for producing a display device, comprising acrosspiece-forming step of forming a plurality of crosspieces atportions other than actuator elements, of an actuator substrate arrangedwith the actuator elements of a number corresponding to a large numberof pixels; a pixel-forming step of forming pixel structures on therespective actuator elements of the actuator substrate; a firstlaminating step of using a jig including, on one surface of a platemember, a large number of size-defining members formed to havesubstantially the same height as that of the crosspieces to be formed onthe actuator substrate to laminate a surface of the jig formed with thesize-defining members and a surface of the actuator substrate formedwith the crosspieces and the pixel structures with each other; apressurizing step of pressurizing the jig and the actuator substrate indirections to make approach to one another; and a second laminating stepof removing the jig, and then laminating an optical waveguide plate onat least the crosspieces on the actuator substrate (invention as definedin claim 27).

In this method, the pixel structures and crosspieces are formed on theactuator substrate. The actuator substrate and the jig including theplate member provided with the large number of size-defining members arelaminated with each other to pressurize them. Thus, the size of thecrosspieces and the pixel structures is defined. After that, the jig isremoved, and the optical waveguide plate is laminated.

Also in this aspect, for example, when the jig is constructed by amember having rigidity such as metal, the waviness of the actuatorsubstrate formed with the pixel structures and the crosspieces can bereduced by laminating and pressurizing the jig and the actuatorsubstrate. The crosspieces and the pixel structures can be formed highlyaccurately.

According to still another aspect of the present invention, there isprovided a method for producing a display device, comprising acrosspiece-forming step of forming a plurality of crosspieces atportions other than actuator elements, of an actuator substrate arrangedwith the actuator elements of a number corresponding to a large numberof pixels; a pixel-forming step of using a jig including, on one surfaceof a plate member, a large number of size-defining members formed tohave substantially the same height as that of the crosspieces to beformed on the actuator substrate to form pixel structures at portionscorresponding to the large number of pixels, the portions being formedwith no size-defining member, of a surface of the jig formed with thesize-defining members; a first laminating step of laminating the surfaceof the jig formed with the size-defining members and the pixelstructures and a surface of the actuator substrate formed with thecrosspieces with each other; a pressurizing step of pressurizing the jigand the actuator substrate in directions to make approach to oneanother; and a second laminating step of removing the jig to transferthe pixel structures to the actuator substrate, and then laminating anoptical waveguide plate on at least the crosspieces on the actuatorsubstrate (invention as defined in claim 28).

In this method, the crosspieces are formed on the actuator substrate.The pixel structures are formed on the jig including the plate memberprovided with the large number of size-defining members. The actuatorsubstrate and the jig are laminated with each other to pressurize them.Thus, the size of the crosspieces and the pixel structures is defined.After that, the jig is removed, the pixel structures are transferred tothe actuator substrate, and then the optical waveguide plate islaminated.

Also in this aspect, for example, when the jig is constructed by amember having rigidity such as metal, the waviness of the actuatorsubstrate formed with the pixel structures can be reduced by laminatingand pressurizing the jig and the actuator substrate. The crosspieces andthe pixel structures can be formed highly accurately.

According to still another aspect of the present invention, there isprovided a method for producing a display device, comprising acrosspiece-forming step of using a jig including, on one surface of aplate member, a large number of size-defining members formed to havesubstantially the same height as that of crosspieces to be formed on anactuator substrate to form the plurality of crosspieces at portionsformed with no size-defining member, of a surface of the jig formed withthe size-defining members, the portions being other than portionscorresponding to a large number of pixels; a pixel-forming step offorming pixel structures at portions corresponding to the large numberof pixels, the portions being formed with no size-defining member, ofthe surface of the jig formed with the size-defining members; a firstlaminating step of laminating the actuator substrate arranged withactuator elements of a number corresponding to the large number ofpixels on the crosspieces and the pixel structures on the jig; apressurizing step of pressurizing the jig and the actuator substrate indirections to make approach to one another; and a second laminating stepof removing the jig to transfer the crosspieces and the pixel structuresto the actuator substrate, and then laminating an optical waveguideplate on at least the crosspieces (invention as defined in claim 29).

In this method, the crosspieces and the pixel structures are formed onthe jig including the plate member formed with the large number ofsize-defining members. The jig and the actuator substrate are laminatedwith each other to pressurize them. Thus, the size of the crosspiecesand the pixel structures is defined. After that, the jig is removed, thecrosspieces and the pixel structures are transferred to the actuatorsubstrate, and the optical waveguide plate is laminated.

Also in this aspect, for example, when the jig is constructed by amember having rigidity such as metal, the waviness of the actuatorsubstrate can be reduced by laminating and pressurizing the jig and theactuator substrate. The crosspieces and the pixel structures can betransferred to the actuator substrate highly accurately.

In the production methods in which the crosspieces are formed on theplate member or the jig, of the production methods described above, itis also preferable that the members for constructing the crosspieces arelaminated on the plate member or the jig by utilizing surface tension ofliquid (invention as defined in claim 30). In this arrangement, theplate member or the jig can be easily removed thereafter.

In the production methods in which the crosspieces are formed on theplate member or the jig, of the production methods described above, itis also preferable that the crosspieces are formed at the concerningportions of the plate member or the jig, and then the crosspieces arehardened (invention as defined in claim 31).

It is also preferable that in the pressurizing step of the productionmethods described above, at least the pixel structures are hardenedwhile pressurizing the actuator substrate and the member to bepressurized together with the actuator substrate (invention as definedin claim 32). It is also preferable that the optical waveguide plateincludes a gap-forming layer at a portion corresponding to thecrosspiece (invention as defined in claim 33).

In the methods described above, it is also preferable that a gap-forminglayer is previously formed on the crosspiece before laminating theoptical waveguide plate (invention as defined in claim 34). In thisarrangement, the presence of the gap-forming layer makes it easier toobtain a uniform gap between the pixel structure and the opticalwaveguide plate for all of the pixels. The size of the gap can be easilycontrolled as well.

When the optical waveguide plate, the plate member, or the jig islaminated and pressurized in the state in which at least the pixelstructures are not hardened upon the lamination of the plate member orthe jig and the actuator substrate or upon the lamination of the opticalwaveguide plate and the actuator substrate, the optical waveguide plate,the plate member, or the jig presses the crosspieces and the pixelstructures toward the actuator substrate during the pressurizingprocess. The upper surface of the crosspiece and the upper surface ofthe pixel structure form a substantially identical surface at least whenthe pixel structures are hardened.

In this arrangement, a material, with which the pixel structure iscontracted upon the hardening of the pixel structure, is used as theconstitutive material for the pixel structure. By doing so, it ispossible to form a gap between the pixel structure and the opticalwaveguide plate during the hardening of the crosspiece and the pixelstructure.

Other methods are available to form the gap. That is, for example, whenthe optical waveguide plate is laminated and pressurized, the pixelstructure is heated and expanded, or the actuator element is displacedto allow the pixel structure to make contact with the optical waveguideplate. It is also possible to adopt a combination of the methods asdescribed above. After that, when the crosspiece and the pixel structureare hardened, a constant gap is formed between the pixel structure andthe optical waveguide plate in accordance with the contraction of thepixel structure or the displacement reset (restoration) of the actuatorelement.

Another arrangement is available, in which the pixel structure contactswith the optical waveguide plate in the natural state. This arrangementis applicable to a case in which the displacement action of the actuatorelement resides in displacement in a direction in which the pixelstructure is separated from the optical waveguide plate.

In the production methods described above, it is preferable that thecrosspiece is hardened, or the crosspiece is partially hardened when theplate member or the optical waveguide plate is laminated on the actuatorsubstrate. In this arrangement, the crosspiece acts as a spacer todefine the distance between the actuator substrate and the plate memberor the optical waveguide plate.

It is also preferable that when the actuator substrate and the member(the optical waveguide plate, the plate member, or the jig) to bepressurized together with, the actuator substrate are pressurized, apreliminary treatment is performed for gap formation, and apredetermined gap is formed between the pixel structure and the opticalwaveguide plate during the hardening of at least the pixel structuresperformed thereafter (invention as defined in claim 35).

This arrangement resides in the method having been already explained.That is, when the optical waveguide plate, the plate member, or the jigis laminated and pressurized, the pixel structure is heated andexpanded, or the actuator element s, displaced to allow the pixelstructure to make contact with the optical waveguide plate, the platemember, or the jig. When this method is adopted, it is easy to form aconstant gap between the pixel structures and the optical waveguideplate. It is possible to obtain a uniform brightness for all of thepixels.

Especially, it is preferable that a vacuum packaging method is used topressurize the actuator substrate and the member (the optical waveguideplate, the plate member, or the jig) to be pressurized together with theactuator substrate (invention as defined in claim 36). That is, forexample, even when the actuator substrate involves warpage and waviness,it is possible to uniformly pressurize the actuator substrate and theoptical waveguide plate, the plate member, or the jig. Accordingly, theoptical waveguide plate, the plate member, or the jig and the actuatorsubstrate are adopted to one another. Therefore, when the opticalwaveguide plate is laminated, a constant gap can be finally formedbetween all of the pixel structures and the optical waveguide plate.

If the thickness is dispersed among the pixel structures, thedisplacement (displacement amount) of the actuator element after theformation of the pixel is greatly dispersed. However, according to thismethod, the thickness is uniformly formed for all of the pixelstructures. Therefore, it is possible to suppress such dispersion indisplacement (displacement amount) of the actuator element.

Owing to the fact that the dispersion scarcely occurs in the thicknessof the pixel structure, there is no dispersion in deformation of thepixel structure caused by thermal expansion or contraction. It isadvantageous that the dispersion hardly appears in gap amount even whenany heat is exerted.

It is also preferable that a low pressure press method is used topressurize the actuator substrate and the member (the optical waveguideplate, the plate member, or the jig) to be pressurized together with theactuator substrate (invention as defined in claim 37). In thisarrangement, it is possible to decrease the stress applied to theactuator substrate. Therefore, it is possible to avoid any damage or thelike of the actuator element. Further, little deformation occurs in theactuator substrate and the optical waveguide plate due to thelamination, and the residual stress is small. Accordingly, it ispossible to improve the stability and the durability of the gap.

In the methods described above, it is also preferable that the member(the plate member or the jig), which is used to be laminated on theactuator substrate in the first laminating step, has a projection at aportion corresponding to each of the pixel structures, and a recesscorresponding to the projection is formed on the surface of the pixelstructure when the plate member or the jig and the actuator substrateare pressurized (invention as defined in claim 38).

In the methods described above, it is also preferable that the member(the plate member or the jig), which is used to be laminated on theactuator substrate in the first laminating step, has a projection at aportion corresponding to each of the pixel structures, and a stepcorresponding to the projection is formed on the surface of the pixelstructure when the plate member or the jig and the actuator substrateare pressurized (invention as defined in claim 39).

In the methods described above, it is also preferable that the member(the plate member or the jig), which is used to be laminated on theactuator substrate in the first laminating step, has a convexconfiguration formed at a portion corresponding to each of the pixelstructures.,and a concave configuration corresponding to the convexconfiguration is formed on the surface of the pixel structure when theplate member or the jig and the actuator substrate are pressurized(invention as defined in claim 40).

The crosspiece and the pixel structure may be formed by using the filmformation method and the ceramic sintering method. The film formationmethod includes the thick film formation method such as the screenprinting, the photolithography method, the film lamination method, thespray dipping, the application, and the stamping (the method for placinga liquid material as if a stamp is put); and the thin film formationmethod such as the ion beam, the sputtering, the vacuum evaporation, theion plating, CVD, and the plating.

The plate member having the projection on the surface is used in themethod for forming the recess and the step on the surface of the pixelstructure. For this purpose, it is preferable to use a method in which ametal film or a resist film is formed by the general thin film formationmethod on a plate member composed of glass. This method is advantageousin that the pattern and the height of the projection can be arbitrarilychanged. It is preferable that the height of the projection is about 0.1to 2 μm.

Other methods are available to form the recess or the step on thesurface of the pixel structure. It is possible to use the planepolishing and the laser beam-based surface processing for the surface ofthe pixel structure. The laser processing is not directed to theformation of the recess, but it also has an effect of surfaceimprovement by means of heating. Further, it is possible to arbitrarilydesign the processing pattern. Therefore, the laser processing is usedespecially preferably.

The method for forming the concave configuration of the surface of thepixel structure includes a method of heating and a method in which avoltage is applied to the actuator element during the hardening of thepixel structure. There are a method in which heating is effected duringthe figuring hardening with the plate member, and a method in whichheating is effected after removing the plate member. It is possible toselect the method depending on the material quality of the pixelstructure. The usable heating temperature is 15° C. to 150° C.Especially, a temperature of 20° C. to 80° C. is preferably used.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an arrangement illustrating a display device according to afirst embodiment;

FIG. 2 shows a first illustrative arrangement of the actuator elementand the pixel structure;

FIG. 3 shows an example of the planar configuration of a pair ofelectrodes formed on the actuator element;

FIG. 4A illustrates an example in which comb teeth of the pair ofelectrodes are arranged along the major axis of the shape-retaininglayer;

FIG. 4B illustrates another example;

FIG. 5A illustrates an example in which comb teeth of the pair ofelectrodes are arranged along the minor axis of the shape-retaininglayer;

FIG. 5B illustrates another example;

FIG. 6 shows an arrangement illustrating another example of the pair ofelectrodes formed on the actuator element;

FIG. 7 shows an arrangement illustrating the display device when theactuator element is subjected to the bending displacement in the seconddirection to be convex toward the hollow space;

FIG. 8 shows a second illustrative arrangement of the actuator elementand the pixel structure;

FIG. 9 shows a third illustrative arrangement of the actuator elementand the pixel structure;

FIG. 10 shows a fourth illustrative arrangement of the actuator elementand the pixel structure;

FIG. 11 illustrates an arrangement in which the crosspieces are formedat portions around four corners of the pixel structures respectively;

FIG. 12 illustrates an arrangement of the crosspiece concerning a firstmodified embodiment;

FIG. 13 illustrates an arrangement of the crosspiece concerning a secondmodified embodiment;

FIG. 14 illustrates an arrangement of the crosspiece concerning a thirdmodified embodiment;

FIG. 15 illustrates an arrangement of the crosspiece concerning a fourthmodified embodiment;

FIG. 16 illustrates an arrangement of the crosspiece concerning a fifthmodified embodiment;

FIG. 17 shows the displacement characteristic of the actuator element toexplain the gradation control based on the voltage modulation system;

FIG. 18 illustrate the dot area and the contact state of the pixel andthe principle of the gradation control based on the evanescent effect;

FIG. 19 shows an arrangement illustrating a display device according toa second embodiment;

FIG. 20 shows an arrangement illustrating a modified embodiment of thedisplay device according to a second embodiment;

FIG. 21 shows an arrangement illustrating a display device according toa third embodiment;

FIG. 22 shows an arrangement illustrating a display device according toa fourth embodiment;

FIG. 23 shows an arrangement illustrating a display device according toa fifth embodiment;

FIG. 24 shows an arrangement illustrating a display device according toa sixth embodiment;

FIG. 25 shows a perspective view illustrating a large screen displayapparatus based on the display device according to the first to sixthembodiments, as viewed from the back side;

FIGS. 26A to 26C show production steps illustrating a first productionmethod;

FIGS. 27A to 27C show production steps illustrating a first method ofphotolithography;

FIGS. 28A to 28C show production steps illustrating a second method ofphotolithography;

FIG. 29 illustrates a film lamination method;

FIG. 30 illustrates a vacuum packaging method;

FIG. 31 illustrates a low pressure press method;

FIGS. 32A to 32D show production steps illustrating a second productionmethod;

FIGS. 33A to 33C show production steps illustrating a third productionmethod;

FIG. 34 illustrates a state in which a plate member having projectionsis used to form a plurality of recesses on the pixel structure;

FIG. 35 illustrates a state in which a plate member having a projectionis used to form a step on the pixel structure;

FIG. 36 illustrates a state in which a plate member having a convexconfiguration is used to form a concave configuration on the pixelstructure;

FIG. 37 illustrates a state in which a plate member having projectionsis used to form the upper end of the pixel structure which is higherthan the upper end of the crosspiece;

FIGS. 38A to 38B show production steps illustrating an example in whichthe optical waveguide plate is directly laminated on the upper surfacesof the crosspieces, concerning the third and fourth production methods;

FIGS. 39A to 39D show production steps illustrating the fourthproduction method;

FIGS. 40A to 40B show production steps illustrating an example in whichthe optical waveguide plate is laminated on the upper surfaces of thecrosspieces after forming the gap-forming layer on the optical waveguideplate, concerning the third and fourth production methods;

FIGS. 41A to 41C show production steps illustrating a fifth productionmethod;

FIGS. 42A to 42C show production steps illustrating a sixth productionmethod;

FIGS. 43A and 43B show production steps illustrating a seventhproduction method;

FIGS. 44A to 44C show production steps illustrating an eighth productionmethod (No. 1);

FIGS. 45A and 45B show production steps illustrating the eighthproduction method (No. 2);

FIGS. 46A to 46C show production steps illustrating a ninth productionmethod (No. 1);

FIGS. 47A and 47B show production steps illustrating the ninthproduction method (No. 2);

FIG. 48 illustrates a state in which the crosspieces composed of thefilm are laminated on the plate member by utilizing the surface tensionof the liquid (for example, water);

FIGS. 49A to 49C show production steps illustrating a tenth productionmethod (No. 1);

FIGS. 50A and 50B show production steps illustrating the tenthproduction method (No. 2);

FIGS. 51A to 51C show production steps illustrating an eleventhproduction method (No. 1);

FIGS. 52A and 52B show production steps illustrating the eleventhproduction method (No. 2);

FIGS. 53A to 53C show production steps illustrating a twelfth productionmethod (No. 1);

FIGS. 54A and 54B show production steps illustrating the twelfthproduction method (No. 2);

FIGS. 55A to 55C show production steps illustrating a thirteenthproduction method (No. 1);

FIGS. 56A and 56B show production steps illustrating the thirteenthproduction method (No. 2);

FIGS. 57A to 57C show production steps illustrating a fourteenthproduction method (No. 1);

FIGS. 58A and 58B show production steps illustrating the fourteenthproduction method (No. 2);

FIGS. 59A to 59C show production steps illustrating a fifteenthproduction method (No. 1);

FIGS. 60A and 60B show production steps illustrating the fifteenthproduction method (No. 2);

FIGS. 61A to a 61B show production steps illustrating a sixteenthproduction method (No. 1);

FIGS. 62A and 62B show production steps illustrating the sixteenthproduction method (No. 2); and

FIG. 63 shows an arrangement of the display device concerning theillustrative example suggested by the present applicant.

BEST MODE FOR CARRYING OUT THE INVENTION

Several illustrative embodiments of the display device and the methodfor producing the display device according to the present invention willbe explained below with reference to FIGS. 1 to 62B.

As shown in FIG. 1, a display device Da according to the firstembodiment comprises an optical waveguide plate 12 for introducing light10 from a light source 100 thereinto, and a driving section 16 providedopposingly to the back surface of the optical waveguide plate 12 andincluding a large number of actuator elements 14 which are arrangedcorresponding to pixels in a matrix configuration or in a zigzagconfiguration.

A pixel structure 102 is stacked on each of the actuator elements 14.The pixel structure 102 functions to increase the contact area withrespect to the optical waveguide plate 12 so that the area correspondingto the pixel is obtained.

The driving section 16 includes an actuator substrate 18 composed of,for example, ceramics. The actuator elements 14 are arranged atpositions corresponding to the respective pixels on the actuatorsubstrate 18. The actuator substrate 18 has its first principal surfacewhich is arranged to oppose to the back surface of the optical waveguideplate 12. The first principal surface is a continuous surface (flushedsurface). Hollow spaces 20 for forming respective vibrating sections asdescribed later on are provided at positions corresponding to therespective pixels at the inside of the actuator substrate 18. Therespective hollow spaces 20 communicate with the outside viathrough-holes 18 a each having a small diameter and provided at a secondprincipal surface of the actuator substrate 18.

The portion of the actuator substrate 18, at which the hollow space 20is formed, is thin-walled. The other portion of the actuator substrate18 is thick-walled. The thin-walled portion has a structure which tendsto undergo vibration in response to external stress, and it functions asa vibrating section 22. The portion other than the hollow space 20 isthick-walled, and it functions as a fixed section 24 for supporting thevibrating section 22.

That is, the actuator substrate 18 has a stacked structure comprising asubstrate layer 18A as a lowermost layer, a spacer layer 18B as anintermediate layer, and a thin plate layer 18C as an uppermost layer.The actuator substrate 18 can be recognized as an integrated structureincluding the hollow spaces 20 formed at the positions in the spacerlayer 18B corresponding to the pixels. The substrate layer 18A functionsas a substrate for reinforcement, as well as it functions as a substratefor wiring. The actuator substrate 18 may be sintered in an integratedmanner, or it may be additionally attached.

Specified embodiments of the actuator element 14 and the pixel structure102 will now be explained with reference to FIGS. 2 to 10. Theembodiments shown In FIGS. 2 to 10 are illustrative of the structure inwhich the gap-forming layer 50 is formed between the crosspieces 70 andthe optical waveguide plate 12 as described later on.

At first, as shown in FIG. 2, each of the actuator elements 14 comprisesthe vibrating section 22 and the fixed section 24 described above, aswell as a shape-retaining layer 26 composed of, for example, apiezoelectric/electrostrictive layer or an anti-ferroelectric layerdirectly formed on the vibrating section 22, and a pair of electrodes 28(a row electrode 28 a and a column electrode 28 b) formed on an uppersurface of the shape-retaining layer 26.

The pair of electrodes 28 may have a structure in which they are formedon upper and lower sides of the shape-retaining layer 26, or they areformed on only one side of the shape-retaining layer 26. However, inorder to advantageously joint the actuator substrate 18 and theshape-retaining layer 26, it is preferable that the pair of electrodes28 are formed only on the upper side (the side opposite to the actuatorsubstrate 18) of the shape-retaining layer 26 so that the actuatorsubstrate 18 directly contacts with the shape-retaining layer 26 withoutany difference in height, as in this embodiment.

The planar configuration of the pair of electrodes 28 may be a shape inwhich a large number of comb teeth are opposed to one another in acomplementary manner as shown in FIG. 3. Alternatively, it is possibleto adopt, for example, the spiral configuration and the branchedconfiguration as disclosed in Japanese Laid-Open Patent Publication No.10-78549 as well.

When the planar configuration of the shape-retaining layer 26 is, forexample, an elliptic configuration, and the pair of electrodes 28 areformed to have a comb teeth-shaped configuration, then it is possible touse, for example, a form in which the comb teeth of the pair ofelectrodes 28 are arranged along the major axis of the shape-retaininglayer 26 as shown in FIGS. 4A and 4B, and a form in which the comb teethof the pair of electrodes 28 are arranged along the minor axis of theshape-retaining layer 26 as shown in FIGS. 5A and 5B.

It is possible to use, for example, the form in which the comb teeth ofthe pair of electrodes 28 are included in the planar configuration ofthe shape-retaining layer 26 as shown in FIGS. 4A and 5A, and the formin which the comb teeth of the pair of electrodes 28 protrude from theplanar configuration of the shape-retaining layer 26 as shown in FIGS.4B and 5B. The form shown in FIGS. 4B and 5B are more advantageous toeffect the bending displacement of the actuator element 14.

The pair of electrodes 28 are arranged, for example, as follows as shownin FIG. 6. That is, the row electrode 28 a is formed on the lowersurface of the shape-retaining layer 26, and the column electrode 28 bis formed on the upper surface of the shape-retaining layer 26.

In this embodiment, as shown in FIG. 1, the actuator element 14 can beallowed to make bending displacement in the first direction so that itis convex toward the optical waveguide plate 12. Alternatively, as shownin FIG. 7, the actuator element 14 can be allowed to make bendingdisplacement in the second direction so that it is convex toward thehollow space 20.

On the other hand, as shown in FIG. 2, for example, the pixel structure102 can be constructed as a stacked structure comprising a transparentlayer 48, a color filter 40, and a white scattering element 32 to serveas a displacement transmitting section formed on the actuator element14.

Further, as shown in FIG. 8, a light-reflective layer 72 may be allowedto intervene as a layer disposed under the white scattering element 32.In this arrangement, when the light-reflective layer 72 is composed of aconductive layer such as those made of metal, it is feared that a shortcircuit may be formed between the pair of electrodes 28 a, 28 b of theactuator element 14. Therefore, it is desirable that an insulative layer74 is formed between the light-reflective layer 72 and the actuatorelement 14.

Another example of the pixel structure 102 is shown, for example, inFIG. 9. That is, the pixel structure 102 can be also constructed by astacked structure comprising a as transparent layer 48 and a colorscattering element 44 also used as the displacement-transmitting sectionformed on the actuator element 14. Also in this case, as shown in FIG.10, a light-reflective layer 72 and an insulative layer 74 may beallowed to intervene between the actuator element 14 and the colorscattering element 44.

As shown in FIG. 1, the display device Da according to the firstembodiment comprises the crosspiece 70 formed at the portion other thanthe pixel structure 102 between the optical waveguide plate 12 and theactuator substrate 18. The embodiment shown in FIG. 1 is illustrative ofthe case in which the optical waveguide plate 12 is directly secured tothe upper surface of the crosspiece 70. It is preferable that thematerial for the crosspiece 70 is not deformable against the heat andthe pressure.

The crosspieces 70 can be formed, for example, at portions around fourcorners of the pixel structures 102. As shown in FIG. 11, the portionsaround four corners of the pixel structure 102 are exemplified bypositions corresponding to the respective corners, for example, when thepixel structure 102 has a rectangular or elliptic planar configuration.The portions refer to a form in which one crosspiece 70 is shared by theadjoining pixel structure 102.

Next, several modified embodiments of the arrangement of the crosspiece70 will be explained with reference to FIGS. 12 to 16.

At first, the crosspiece according to the first modified embodiment isshown in FIG. 12. The crosspiece 70 includes windows 70 a forsurrounding at least one pixel structure 102. The representativeillustrative arrangement is as follows. That is, for example, thecrosspiece 70 itself is formed to have a plate-shaped configuration, andthe windows (openings) 70 a each having a shape similar to the outercontour of the pixel structure 102 are formed at the positionscorresponding to the pixel structures 102. Accordingly, an arrangementis given, in which all of the side surfaces of the pixel structures 102are surrounded by the crosspiece 70. Thus, the actuator substrate 18 andthe optical waveguide plate 12 are secured to one another more tightly.

As shown in FIG. 13, the crosspiece according to the second modifiedembodiment includes stripe-shaped openings 220 each of which extends inthe direction of the array of the pixel structures and each of whichsurrounds the array of the pixel structures. Each of the openings 220has an opening width which is enough to include one or more arrays. Thisembodiment is illustrative of a case in which the opening 220 has anopening width which includes one array of the group of pixel structures102.

As shown in FIG. 14, the crosspiece 70 according to the third modifiedembodiment has a shape extending linearly along the direction of thearray of the pixel structures 102. In this arrangement, as in acrosspiece 70 according to a fourth modified embodiment shown in FIG.15, for example, it is also preferable to use a wire member 222 having asubstantially circular cross section. The embodiment shown in FIG. 15 isillustrative of the case in which the wire member 222 for constructingthe crosspiece 70 is secured to the actuator substrate 18 by using anadhesive 224. The cross-sectional configuration of the wire member 222include, for example, the circular configuration as described above aswell as elliptic configurations and polygonal configurations such ashexagon and octagon.

As shown in FIG. 16, the crosspiece 70 according to the fifth modifiedembodiment is arranged and formed with ceramics integrally with theactuator substrate 18 at portions other than the pixel structures 102,of the actuator substrate 18.

In this embodiment, it is possible to improve the mechanical strength ofthe portion at which the crosspiece 70 is formed on the actuatorsubstrate 18. Accordingly, the rigidity of the actuator substrate 18 isenhanced. As a result, for example, the crosspiece 70 can be used toprotect the actuator element 14, especially the vibrating section 22thereof formed on the actuator substrate 18 when the actuator substrate18 is carried and stored.

Explanation will now be made for the respective constitutive componentsof the display device Da, especially, for example, for selection ofmaterials for the respective constitutive components.

The light 10 to be introduced into the optical waveguide plate 12 may beany one of those of ultraviolet, visible, and infrared regions. Thoseusable as the light source 100 include, for example, incandescent lamp,deuterium discharge lamp, fluorescent lamp, mercury lamp, metal halidelamp, halogen lamp, xenon lamp, tritium lamp, light emitting diode,laser, plasma light source, hot cathode tube, and cold cathode tube.

It is preferable that the vibrating section 22 is composed of a highlyheat-resistant material, because of the following reason. That is, whenthe actuator element 14 has the structure in which the vibrating section22 is directly supported by the fixed section 24 without using anymaterial such as an organic adhesive which is inferior in heatresistance, the vibrating section 22 is preferably composed of a highlyheat-resistant material so that the vibrating section 22 is notdeteriorated in quality at least during the formation of theshape-retaining layer 26.

It is preferable that the vibrating section 22 is composed of anelectrically insulative material in order to electrically separate thewiring (for example, row selection line) connected to the row electrode28 a of the pair of electrodes 28 formed on the actuator substrate 18,from the wiring (for example, signal line) connected to the columnelectrode 28 b.

Therefore, the vibrating section 22 may be composed of a material suchas a highly heat-resistant metal and a porcelain enamel produced bycoating a surface of such a metal with a ceramic material such as glass.However, the vibrating section 22 is optimally composed of ceramics.

Those usable as the ceramics for constructing the vibrating section 22include, for example, stabilized zirconium oxide, aluminum oxide,magnesium oxide, titanium oxide, spinel, mullite, aluminum nitride,silicon nitride, glass, and mixtures thereof. Stabilized zirconium oxideis especially preferred because of, for example, high mechanicalstrength obtained even when the thickness of the vibrating section 22 isthin, high toughness, and small chemical reactivity with theshape-retaining layer 26 and the pair of electrodes 28. The term“stabilized zirconium oxide” includes stabilized zirconium oxide andpartially stabilized zirconium oxide. Stabilized zirconium oxide has acrystal structure such as cubic crystal, and hence it does not causephase transition.

On the other hand, zirconium oxide causes phase transition betweenmonoclinic crystal and tetragonal crystal at about 1000° C. Cracksappear during the phase transition in some cases. Stabilized zirconiumoxide contains 1 to 30 mole % of a stabilizer such as calcium oxide,magnesium oxide, yttrium oxide, scandium oxide, ytterbium oxide, ceriumoxide, and oxides of rare earth metals. In order to enhance themechanical strength of the vibrating section 22, the stabilizerpreferably comprises yttrium oxide. In this composition, yttrium oxideis contained preferably in an amount of 1.5 to 6 mole %, and morepreferably 2 to 4 mole %. It is preferable that aluminum oxide isfurther contained in an amount of 0.1 to 5 mole %.

The crystal phase may be, for example, a mixed phase of cubiccrystal+monoclinic crystal, a mixed phase of tetragonalcrystal+monoclinic crystal, and a mixed phase of cubiccrystal+tetragonal crystal+monoclinic crystal. However, among them, mostpreferred are those having a principal crystal phase composed oftetragonal crystal or a mixed phase of tetragonal crystal+cubic crystal,from viewpoints of strength, toughness, and durability.

When the vibrating section 22 is composed of ceramics, a large number ofcrystal grains construct the vibrating section 22. In order to increasethe mechanical strength of the vibrating section 22, the crystal grainspreferably have an average grain diameter of 0.05 to 2 μm, and morepreferably 0.1 to 1 μm.

The fixed section 24 preferably composed of ceramics. The fixed section24 may be composed of the same ceramic material as that used for thevibrating section 22, or the fixed section 24 may be composed of aceramic material different from that used for the vibrating section 22.Those usable as the ceramic material for constructing the fixed section24 include, for example, stabilized zirconium oxide, aluminum oxide,magnesium oxide, titanium oxide, spinel, mullite, aluminum nitride,silicon nitride, glass, and mixtures thereof, in the same manner as thematerial for the vibrating section 22.

Especially, those preferably adopted for the actuator substrate 18 usedin the display device Da according to the first embodiment include, forexample, materials containing a major component of zirconium oxide,materials containing a major component of aluminum oxide, and materialscontaining a major component of a mixture thereof. Among them, thosecontaining a major component of zirconium oxide are more preferable.

Clay or the like is added as a sintering aid in some cases. However, itis necessary to control components of the sintering aid in order not tocontain an excessive amount of those liable to form glass, such assilicon oxide and boron oxide because of the following reason. That is,although the materials which are liable to form glass are advantageousto join the actuator substrate 18 to the shape-retaining layer 26, thematerials facilitate the reaction between the actuator substrate 18 andthe shape-retaining layer 26, making it difficult to maintain apredetermined composition of the shape-retaining layer 26. As a result,the materials make a cause to deteriorate the element characteristics.

That is, it is preferable that silicon oxide or the like in the actuatorsubstrate 18 is restricted to have a weight ratio of not more than 3%,and more preferably not more than 1%. The term “major component” hereinrefers to a component which exists in a proportion of not less than is50% in weight ratio.

As described above, those usable as the shape-retaining layer 26 includepiezoelectric/electrostrictive layers and anti-ferroelectric layers.However, when the piezoelectric/electrostrictive layer is used as theshape-retaining layer 26, those usable as thepiezoelectric/electrostrictive layer include ceramics containing, forexample, lead zirconate, lead magnesium niobate, lead nickel niobate,lead zinc niobate, lead manganese niobate, lead magnesium tantalate,lead nickel tantalate, lead antimony stannate, lead titanate, bariumtitanate, lead magnesium tungstate, and lead cobalt niobate, or anycombination of them.

It is needless to say that the major component contains the compound asdescribed above in an amount of not less than 50% by weight. Among theceramics described above, the ceramics containing lead zirconate is mostfrequently used as the constitutive material for thepiezoelectric/electrostrictive layer for constructing theshape-retaining layer 26.

When the piezoelectric/electrostrictive layer is composed of ceramics,it is also preferable to use ceramics obtained by appropriately adding,to the ceramics described above, oxide of, for example, lanthanum,calcium, strontium, molybdenum, tungsten, barium, niobium, zinc, nickel,and manganese, or any combination thereof or another type of compoundthereof. For example, it is preferable to use ceramics containing amajor component composed of lead magnesium niobate, lead zirconate, andlead titanate and further containing lanthanum and strontium.

The piezoelectric/electrostrictive layer may be either dense or porous.When the piezoelectric/electrostrictive layer is porous, its porosity ispreferably not more than 40%.

When the anti-ferroelectric layer is used as the shape-retaining layer26, it is desirable to use, as the anti-ferroelectric layer, a compoundcontaining a major component composed of lead zirconate, a compoundcontaining a major component composed of lead zirconate and leadstannate, a compound obtained by adding lanthanum to lead zirconate, anda compound obtained by adding lead zirconate and lead niobate to acomponent composed of lead zirconate and lead stannate.

Especially, when an anti-ferroelectric film, which contains leadzirconate and lead stannate as represented by the following composition,is applied as a film-type element such as the actuator element 14, it ispossible to perform driving at a relatively low voltage. Therefore,application of such an anti-ferroelectric film is especially preferred.

Pb_(0.99)Nb_(0.02)[(Zr_(x)Sn_(1−x))_(1−y)Ti_(y)]_(0.98)O₃

wherein, 0.5<x<0.6, 0.05<y<0.063, 0.01<Nb<0.03.

The anti-ferroelectric film may be porous. When the anti-ferroelectricfilm is porous, it is desirable that the porosity is not more than 30%.

It is preferable that the thickness of the vibrating section 22 of theactuator substrate 18 have a dimension identical to that of thethickness of the shape-retaining layer 26 formed on the vibratingsection 22, because of the following reason. That is, if the thicknessof the vibrating section 22 is extremely thicker than the thickness ofthe shape-retaining layer 26 (if the former is different from the latterby not less than one figure), when the shape-retaining layer 26 makesshrinkage upon sintering, the vibrating section 22 behaves to inhibitthe shrinkage. For this reason, the stress at the boundary surfacebetween the shape-retaining layer 26 and the actuator substrate 18 isincreased, and consequently they are easily peeled off from each other.On the contrary, when the dimension of the thickness is in an identicaldegree between the both, it is easy for the actuator substrate 18(vibrating section 22) to follow the shrinkage of the shape-retaininglayer 26 upon sintering. Accordingly, such dimension of the thickness ispreferred to achieve integration. Specifically, the vibrating section 22preferably has a thickness of 1 to 100 μm, more preferably 3 to 50 μm,and much more preferably 5 to 20 μm. On the other hand, theshape-retaining layer 26 preferably has a thickness of 5 to 100 μm, morepreferably 5 to 50 μm, and much more preferably 5 to 30 μm.

The pair of electrodes 28 formed on the shape-retaining layer 26 areallowed to have an appropriate thickness depending on the use orapplication. However, the thickness is preferably 0.01 to 50 μm, andmore preferably 0.1 to 5 μm. The pair of electrodes 28 are preferablycomposed of a conductive metal which is solid at room temperature. Themetal includes, for example, metal simple substances or alloyscontaining, for example, aluminum, titanium, chromium, iron, cobalt,nickel, copper, zinc, niobium, molybdenum, ruthenium, rhodium, silver,stannum, tantalum, tungsten, iridium, platinum, gold, and lead. It isneedless to say that these elements may be contained in an arbitrarycombination.

The optical waveguide plate 12 has an optical refractive index withwhich the light 10 introduced into the inside thereof is totallyreflected by the front and back surfaces without being transmitted tothe outside of the optical waveguide plate 12. It is necessary for theoptical waveguide plate 12 to use those having a large and uniform lighttransmittance in the wavelength region of the light to be introduced.The material for the optical waveguide plate 12 is not specificallylimited provided that it satisfies the foregoing characteristic.However, specifically, those generally used for the optical waveguideplate 12 include, for example, glass, quartz, light-transmissiveplastics such as acrylic plastics, light-transmissive ceramics,structural materials comprising a plurality of layers composed ofmaterials having different refractive indexes, and those having asurface coating layer.

The color layer such as the color filter 40 and the color scatteringelement included, in the pixel structure 102 is the layer which is usedto extract only the light in a specified wavelength region, and itincludes, for example, those which develops the color by absorbing,transmitting, reflecting, or scattering the light at a specifiedwavelength, and those which convert incident light into light having adifferent wavelength. The transparent member, the semitransparentmember, and the opaque member can be used singly or in combination.

The color layer is constructed, for example, as follows. That is, thecolor layer includes, for example, those obtained by dispersing ordissolving a dyestuff or a fluorescent material such as dye, pigment,and ion in rubber, organic resin, light-transmissive ceramics, glass,liquid or the like, those obtained by applying the dyestuff or thefluorescent material on the surface of the foregoing material, thoseobtained by sintering, for example, the powder of the dyestuff or thefluorescent material, and those obtained by pressing and solidifying thepowder of the dyestuff or the fluorescent material. As for the materialquality and the structure, the materials may be used singly, or thematerials may be used in combination.

The difference between the color filter 40 and the color scatteringelement 44 lies in whether or not the brightness value of leakage lightobtained by reflection and scattering effected by only the color layeris not less than 0.5-fold the brightness value of leakage light obtainedby reflection and scattering effected by the entire structure includingthe pixel structure 102 and the actuator element 14, when the lightemission state is given by allowing the pixel structure 102 to makecontact with the optical waveguide plate 12 into which the light 10 isintroduced. If the former brightness value is not less than 0.5-fold thelatter brightness value, the color layer is defined to be the colorscattering element 44. If the former brightness value is less than0.5-fold the latter brightness value, the color layer is defined to bethe color filter 40.

The measuring method is specifically exemplified as follows. That is, itis assumed that when the color layer is singly allowed to make contactwith the back surface of the optical waveguide plate 12 into which thelight 10 is introduced, A(nt) represents the front brightness of thelight which passes from the color layer through the optical waveguideplate 12 and which leaks to the front surface. Further, it is assumedthat when the pixel structure 102 is allowed to make contact with thesurface of the color layer on the side opposite to the side to makecontact with the optical waveguide plate 12, B(nt) represents the frontbrightness of the light which leaks to the front surface. If A≧0.5×B issatisfied, the color layer is the color scattering element 44. IfA<0.5×B is satisfied, the color layer is the color filter 40.

The front brightness is the brightness measured by arranging a luminancemeter so that the line to connect the color layer to the luminance meterfor measuring the brightness is perpendicular to the surface of theoptical waveguide plate 12 to make contact with the color layer (thedetection surface of the luminance meter is parallel to the platesurface of the optical waveguide plate).

The color scattering element 44 is advantageous in that the color toneand the brightness are scarcely changed depending on the thickness ofthe layer. Accordingly, those applicable as the method for forming thelayer includes various methods such as the screen printing whichrequires inexpensive cost although it is difficult to strictly controlthe layer thickness.

Owing to the arrangement in which the color scattering element 44 alsoserves as the displacement-transmitting section, it is possible tosimplify the process for forming the layer. Further, it is possible toobtain a thin entire layer thickness. Therefore, the thickness of theentire display device can be made thin. Further, it is possible to avoidthe decrease in displacement amount of the actuator element 14, andimprove the response speed.

The color filter 40 has the following advantages. That is, when thelayer is formed on the side of the optical waveguide plate 12, the layercan be easily formed, because the optical waveguide plate 12 is flat,and it has high surface smoothness. Thus, the range of process selectionis widened, and the cost becomes inexpensive. Further, it is easy tocontrol the layer thickness which may affect the color tone and thebrightness.

The method for forming the film of the color layer such as the colorfilter 40 and the color scattering element 44 is not specificallylimited, to which it is possible to apply a variety of known filmformation methods. Those usable include, for example, a film laminationmethod in which the color layer in a chip form or in a film form isdirectly stuck on the surface of the optical waveguide plate 12 or theactuator element 14, as well as a method for forming the color layer inwhich, for example, powder, paste, liquid, gas, or ion to serve as a rawmaterial for the color layer is formed into a film in accordance withthe thick film formation method such as the screen printing, thephotolithography method, the spray dipping, and the application, or inaccordance with the thin film formation method such as the ion beam, thesputtering, the vacuum evaporation, the ion plating, CVD, and theplating.

Next, the operation of the display device Da according to the firstembodiment will be briefly described with reference to FIG. 1. At first,the light 10 is introduced, for example, from the end portion of theoptical waveguide plate 12. In this embodiment, all of the light 10 istotally reflected at the inside of the optical waveguide plate 12without being transmitted through the front and back surfaces thereof bycontrolling the magnitude of the refractive index of the opticalwaveguide plate 12. In this embodiment, the optical waveguide plate 12desirably has a reflection factor n of 1.3 to 1.8, and more desirably1.4 to 1.7.

In this state, when a certain actuator element 14 is in the selectedstate, the actuator element 14 makes bending displacement so that it isconvex toward the optical waveguide plate 12, i.e., the actuator element14 makes bending displacement in the first direction, and the endsurface of the pixel structure 102 contacts, at a distance of not morethan the wavelength of light 10, with the optical waveguide plate 12,then the light 10, which has been subjected to total reflection, isreflected by the surface of the pixel structure 102, and it behaves asscattered light 42. A part of the scattered light 42 is reflected againin the optical waveguide plate 12. However, almost all of the scatteredlight 42 is not reflected by the optical waveguide plate 12, and it istransmitted through the front surface (face) of the optical waveguideplate 12. Accordingly, the pixel corresponding to the actuator element14 is in the ON state, and the ON state is expressed in a form of lightemission. Further, the color of the light emission corresponds to thecolor of the color filter 40 or the color scattering element 44 includedin the pixel structure 102.

That is, in the display device Da, the presence or absence of lightemission (leakage light) at the front surface of the optical waveguideplate 12 can be controlled depending on the presence or absence of thecontact of the pixel structure 102 with the optical waveguide plate 12.Especially, in the display device Da according to the first embodiment,one unit for making the displacement action of the pixel structure 102in the direction to make contact or separation with respect to theoptical waveguide plate 12 may be recognized, for example, as one pixel.A large number of the pixels are arranged in a matrix configuration orin a zigzag configuration concerning the respective rows. Therefore, itis possible to display a picture image (characters and graphics)corresponding to the image signal on the front surface of the opticalwaveguide plate 12, i.e., on the display surface, in the same manner asin the cathode ray tube, the liquid crystal display device, and theplasma display, by controlling the displacement action in each of thepixels in accordance with the attribute of the inputted image signal.

In the gradation control over the display, for example, it is possibleto adopt the voltage modulation system and the time modulation system.For example, in the voltage modulation system, when one row is selected,for example, voltages corresponding to the gradation of the respectiveactuator elements 14 are applied to a large number of the actuatorelements 14 arranged on the selected row. The respective actuatorelements 14 are displaced in the first direction in accordance with thelevel of the applied voltages. In the case of an example shown in FIG.17, the displacement is made linearly to give displacement amounts ofZ₁, Z₂, . . . Z_(n) for voltages V₁, V₂, . . . V_(n) respectively.

For example, as shown in FIG. 18, at a point of time at which theactuator element 14 is displaced in a displacement amount of Z₁, thedistance D between the first principal surface of the pixel structure102 and the back surface of the optical waveguide plate 12 becomes adistance corresponding to the wavelength λ of the light 10 (the light 10introduced into the optical waveguide plate 12). For example, at a pointof time at which the actuator element 14 is displaced in a displacementamount of Z_(n), ideally the first principal surface of the pixelstructure completely contacts with the back surface of the opticalwaveguide plate 12.

When the pixel structure 102 approaches the bank surface of the opticalwaveguide plate 12, and the distance between the first principal surfaceof the pixel structure 102 and the back surface of the optical waveguideplate 12 is not more than the wavelength λ of the light 10, then theamount of the scattered light radiated from the surface of the opticalwaveguide plate 12 is increased in accordance with the decrease in thedistance, and the brightness level of the pixel corresponding to theactuator element 14 is increased.

This phenomenon can be explained as follows in accordance with theevanescent effect. In general, as shown in FIG. 18, a region (evanescentregion) 104, which is brought about on account of discharge of light(evanescent wave), exists, for example, around the back surface of theoptical waveguide plate 12. The depth dp of the evanescent region 104represents a depth at which the energy value of the evanescent wave is1/e at the boundary between the optical waveguide plate 12 and theexternal space (the back surface of the optical waveguide plate 12 inthis embodiment). The depth dp is given by the following expression (1).The energy E of the evanescent wave is given by the following expression(2).

dp=λ/[2πn ₁{sin²θ(n/n ₂)²}]  (1)

E=exp{⁻(D/dp)}  (2)

In the expression, λ represents the wavelength of the light 10, and θrepresents the angle (angle of incidence) at which the light 10 comesfrom the optical waveguide plate 12 into the external space as shown inFIG. 18. Further, n₁ represents the optical refractive index of theoptical waveguide plate 12, and n₂ represents the optical refractiveindex of the external space.

According to the expression (1), it can be postulated that the depth dpis increased as the wavelength λ of the light 10 is increased, and thedepth dp is increased as the angle of incidence θ approaches thecritical angle. On the other hand, as shown in the expression (2), theenergy E of the evanescent wave is increased as the object approachesthe back surface of the optical waveguide plate 12, and the energy E isattenuated exponentially as the object is separated from the backsurface of the optical waveguide plate 12. The amount of light(scattered light 42) reflected by the surface of the pixel structure 102is proportional to the energy E of the evanescent wave. Accordingly, theamount of scattered light 42 is increased as the pixel structure 102approaches the back surface of the optical waveguide plate 12, and theamount of light 42 is decreased exponentially as the pixel structure 102is separated from the back surface of the optical waveguide plate 12.

In this process, the actuator element 14 continues to retain thedisplacement amount determined upon the selection owing to theshape-retaining effect exerted by the shape-retaining layer 26 of theactuator section 14. Accordingly, the light emission state of the pixelis maintained for a certain period of time.

When the display device is applied to the color display system, forexample, it is preferable to construct one pixel by using three pixelstructures adjacent to one another (RGB arrangement) or four pixelstructures adjacent to one another (checked arrangement or the like),for example, depending on the color scheme of the color filter 40 (forexample, three primary color filters and complementary color filters)included in the pixel structure 102.

As described above, the display device Da according to the firstembodiment comprises the crosspiece 70 at the portions other than thepixel structure 102 between the optical waveguide plate 12 and theactuator substrate 18.

If the optical waveguide plate 12 and the actuator substrate 18 arefixed at only the circumferential edge of the screen without providingthe crosspiece 70, then the displacement standard is changed every timewhen the vibration occurs in the actuator substrate 18 due to themovement of the actuator element 14, and the ON/OFF operation of thepixel does not correspond to the displacement of the actuator element 14in some cases.

However, in the display device Da according to the first embodiment, thecrosspiece 70 is provided as described above. Therefore, even when acertain actuator element 14 makes the displacement action, the vibrationis absorbed by the crosspiece 70. Thus, the inconvenience such as thechange in displacement standard does not take place.

The support for the optical waveguide plate 12, which is effected by thecrosspiece 70 formed around the pixel structure 102, makes it possibleto easily obtain the uniform gap “g” between the pixel structure 102 andthe optical waveguide plate 12 for all of the pixels. Further, the sizeof the gap “g” can be easily controlled by arbitrarily changing theheight of the crosspiece 70. As a result, it is possible to obtain theuniform brightness for all of the pixels.

Especially, as shown in FIG. 11, when the crosspieces 70 are formed atthe portions around the four corners of the pixel structure 102, thearrangement is given, in which the four crosspieces 70 are formed forthe unit of the pixel structure 102. Accordingly, the vibration, whichis caused by the displacement action of a certain actuator element 14 iseffectively absorbed. Little influence is exerted on the displacementaction of the other actuator elements 14. As a result, it is possible toobtain good correspondence between the ON operation/OFF operation andthe displacement for all of the pixels. It is possible to faithfullydisplay the picture image corresponding to the inputted image signal.

Further, the actuator substrate 18 and the optical waveguide plate 12are tightly secured to one another. As shown in FIG. 12, when thecrosspiece 70 has the windows 70 a for surrounding at least one pixelstructure 102, the arrangement is given, in which all of the sidesurfaces of the pixel structure 102 is surrounded by the crosspiece 70.The actuator substrate 18 and the optical waveguide plate 12 are securedto one another more tightly.

Further, the vibration, which is caused by the displacement action of acertain actuator element 14, does not affect the displacement action ofthe other actuator elements 14 at all.

Next, a display device Db according to the second embodiment will beexplained with reference to FIG. 19. Components or parts correspondingto those shown in FIG. 1 are designated by the same reference numerals,duplicate explanation of which will be omitted.

As shown in FIG. 19, the display device Db according to the secondembodiment is constructed in approximately the same manner as thedisplay device Da according to the first embodiment (see FIG. 1).However, the former is different from the latter in that a gap-forminglayer 50 is provided between the forward end of the crosspiece 70 andthe optical waveguide plate 12.

Owing to the presence of the gap-forming layer 50, the gap-forming layer50 can be used to adjust the gap “g” between the pixel structure 102 andthe optical waveguide plate 12. Accordingly, an effect is obtained inthat the gap “g” can be made uniform for all of the pixels. Thisembodiment is advantageous in that the gap “g” can be easily adjustedwhen the position of the upper surface of the pixel structure 102 isaligned with the position of the upper surface of the crosspiece 70(surface to make contact with the gap-forming layer 50).

The method to realize this arrangement includes, for example, a methodin which a flat glass surface is used to simultaneously form the pixelstructure 102 and the crosspiece 70, and a method in which the pixelstructure 102 and the crosspiece 70 are formed, followed by polishing toperform figuring.

The constitutive material for the gap-forming layer 50 includes, forexample, metal films, films containing carbon black, black pigment, orblack dye, and transparent films having low light-scattering property.Accordingly, the gap-forming layer 50 can be allowed to simultaneouslyhave the function of a black matrix.

Especially, when a metal film composed of, for example, Cr, Al, Ni, orAg is used as the gap-forming layer 50, the attenuation and thescattering of the light transmitted through the optical waveguide platecan be suppressed, because of a small amount of light is absorbedthereby. Therefore, such a metal film is used especially preferably.

When a film containing carbon black, black pigment, or black dye is usedas the gap-forming layer 50, then the light-absorbing performance isexcellent, and it is possible to improve the contrast. When atransparent film having a poor light-scattering property is used as thegap-forming layer 50, then the light scattering can be suppressed, andthe contrast can be enhanced by combining the film-with an adhesivehaving an excellent light-absorbing property (or an adhesive having alight-absorbing property enhanced by adding black dye or blackpigment).

The size of the gap-forming layer 50 is set as follows, for example, asexemplified by the case in which the actuator element 14 is displaced tobe convex toward the optical waveguide plate 12. That is, the smalllimit (minimum value) of the gap amount “g” is set to be such a degreethat the leakage of light caused by the evanescent effect upon the OFFoperation of the pixel structure 102 can be neglected. The large limit(maximum value) of the gap amount “g” is set to be within a range inwhich the pixel structure 102 can make contact with the opticalwaveguide plate 12 in accordance with the displacement of the actuatorelement 14. Therefore, the thickness of the gap-forming layer 50 isadjusted so that the gap amount “g” is within the range described above.Especially preferably, the thickness is about 1 to 5 μm. However, thedifference in height between the pixel structure 102 and the crosspiece70 is controllable depending on various embodiments of the displaydevice. The thickness of the gap-forming layer 50 may be optimized inaccordance therewith.

The display device Db according to the second embodiment shown in FIG.19 is illustrative of the case in which the width of the gap-forminglayer 50 is larger than the width of the crosspiece 70. Alternatively,as in a display device Dba according to a modified embodiment shown inFIG. 20, the width of the gap-forming layer 50 may be made smaller thanthe width of the crosspiece 70. In this embodiment, the contact area ofthe gap-forming layer 50 with respect to the optical waveguide plate 12is decreased. Therefore, it is possible to reduce unnecessary scatteredlight. This embodiment is advantageous to improve the contrast.

Next, a display device Dc according to the third embodiment will beexplained with reference to FIG. 21. Components or parts correspondingto those shown in FIG. 19 are designated by the same reference numerals,duplicate explanation of which will be omitted.

As shown in FIG. 21, the display device Dc according to the thirdembodiment is constructed in approximately the same manner as thedisplay device Db according to the second embodiment (see FIG. 19).However, the former is different from the latter in that a plurality ofrecesses 110 are formed on the surface of the pixel structure 102. Therecesses may be formed as a continuous groove.

According to the display device Dc concerning the third embodiment, anapproximately identical contact area with respect to the opticalwaveguide plate 12 can be realized for the respective pixel structures102 by defining the size or the number of formed recesses 110 inconformity with the area of the pixel structure 102 opposing to theoptical waveguide plate 12. Thus, it is possible to obtain a uniformbrightness for all of the pixels.

The presence of the recess 110 mitigates the tight adherence between thepixel structure 102 and the optical waveguide plate 12. The pixelstructure 102 is smoothly separated from the optical waveguide plate 12.As a result the pixel structure 102 can be prevented from adhesion tothe optical waveguide plate 12. Accordingly, it is possible toeffectively realize a high response speed.

Next, a display device Dd according to the fourth embodiment will beexplained with reference to FIG. 22. Components or parts correspondingto those shown in FIG. 19 are designated by the same reference numerals,duplicate explanation of which will be omitted.

As shown in FIG. 22, the display device Dd according to the fourthembodiment is constructed in approximately the same manner as thedisplay device Db according to the second embodiment. However, theformer is different from the latter in that a step 112 is formed at thecircumferential edge of the pixel structure 102.

According to the display device Dd concerning the fourth embodiment, theprovision of the step 112 at the circumferential edge of the pixelstructure 102 makes it possible to obtain a constant area of the portionof the pixel structure 102 to make contact with the optical waveguideplate 12 for all of the pixels. It is possible to obtain a uniformbrightness for all of the pixels. Further, the presence of the step 112mitigates the tight adherence between the pixel structure 102 and theoptical waveguide plate 12. Therefore, the pixel structure 102 can beprevented from adhesion to the optical waveguide plate 12. Accordingly,it is possible to effectively realize a high response speed.

Next, a display device De according to the fifth embodiment will beexplained with reference to FIG. 23. Components or parts correspondingto those shown in FIG. 19 are designated by the same reference numerals,duplicate explanation of which will be omitted.

As shown in FIG. 23, the display device De according to the fifthembodiment is constructed in approximately the same manner as thedisplay device Db according to the second embodiment. However, theformer is different from the latter in that the surface of the pixelstructure 102 is formed to have a concave configuration 114.

When the actuator element 14 makes displacement, the central portion ofthe pixel structure 102 tends to have the largest displacement amount.Therefore, the surface of the pixel structure 102 has the concaveconfiguration 114 so that the central portion of the pixel structure 102is made concave to give the depth, for example, corresponding to thedisplacement amount described above. By doing so, the surface of thepixel structure 102 is approximately flat when the actuator element 14makes displacement to allow the pixel structure 102 to make contact withthe optical waveguide plate 12. Thus, it is possible to increase thecontact area of the pixel structure 102 with respect to the opticalwaveguide plate 12.

In this embodiment, when the depth of the concave curve of the concaveconfiguration 114 is increased, a state is given, in which the centralportion of the pixel structure 102 does not arrive at the opticalwaveguide plate 12 when the pixel structure 102 makes contact with theoptical waveguide plate 12, giving a state in which a recess is formedon the surface of the pixel structure 102 in a simulated manner.Accordingly, the tight adherence between the pixel structure 102 and theoptical waveguide plate 12 is mitigated. Thus, the pixel structure 102is smoothly separated from the optical waveguide plate 12. As a result,the pixel structure 102 can be prevented from adhesion to the opticalwaveguide plate 12, and it is possible to effectively realize a highresponse speed.

The arrangement of the display device Dc according to the thirdembodiment (the recess 110 is formed on the surface of the pixelstructure 102), the arrangement of the display device Dd according tothe fourth embodiment (the step 112 is formed on the surface of thepixel structure 102), and the arrangement of the display device Deaccording to the fifth embodiment (the surface of the pixel structure102 has the concave configuration 114) may be realized singlyrespectively, or they may be arbitrarily combined with each other. Thecombination of them makes it possible to obtain the synergistic effectbased on the respective arrangements. FIG. 24 is illustrative of adisplay device Df according to the sixth embodiment in which all of thearrangements of the display devices Dc to De according to the third tofifth-embodiments are combined with each other.

The display devices Da to Df according to the first to sixth embodimentscan be used singly. Besides, the display devices Da to Df according tothese embodiments may be used as one display element 252 included in alarge screen display apparatus 250 as shown in FIG. 25. FIG. 25 shows anillustrative arrangement in which seven display elements 252 arearranged in the vertical direction, and eighteen display elements 252are arranged in the lateral direction on a back surface of alight-introducing plate 254 having a display area for a large screen. Inthis arrangement, those which have a large and uniform lighttransmittance in the visible light region, such as glass plates andacrylic plates are used for the light-introducing plate 254. Therespective display elements 252 are connected to one another by meansof, for example, wire bonding, soldering, face connector, and backconnector so that signals may be mutually supplied.

The large screen display apparatus 250 shown in FIG. 25 uses the displaydevices Da to Df according to the first to sixth embodiments, as thedisplay devices applied to the respective display elements 252. In eachof the display elements 252, the arrangement of the pixels comprises 32individuals in the horizontal direction and 32 individuals in thevertical direction. In the display devices Da to Df according to theseembodiments, when the pixels concerning the respective rows are arrangedin the zigzag form, it is possible to provide an extremely smallarrangement pitch of the pixels in the horizontal direction. When thenumber of arranged pixels in the horizontal direction is the same asthat in the vertical direction, the entire planar configuration has avertical length which is longer than a horizontal length.

The large screen display apparatus 250 shown in FIG. 25 represents theillustrative arrangement in which the display elements 252 including theoptical waveguide plates 12 are arranged in the matrix form on the platesurface of the large light-introducing plate 254. Alternatively, thelarge light-introducing plate 252 may be omitted so that the largescreen display apparatus 250 is constructed by arranging, in a matrixform, the display elements 252 including the optical waveguide plates12. In such an arrangement, the large number of optical waveguide plates12 arranged in the matrix form also serve as the large light-introducingplate 254. Besides the foregoing arrangements, it is also allowable thatthe large screen display apparatus 250 is constructed by arranging, in amatrix form, display elements 252 without including any opticalwaveguide plate 12 on the plate surface of the large light-introducingplate 254.

It is preferable that the light-introducing plate 254 has a refractiveindex which is similar to that of the optical waveguide plate 12. Whenthe light-introducing plate 254 and the optical waveguide plates 12 arestuck to one another, a transparent adhesive may be used. The adhesivepreferably has a uniform and high transmittance in the visible lightregion, in the same manner as the optical waveguide plate 12 and thelight-introducing plate 254. It is desirable for the adhesive to set itsrefractive index which is near to those of the light-introducing plate254 and the optical waveguide plate 12 in order to ensure brightness ofthe screen.

Next, methods for producing the display devices Da to Df according tothe first to sixth embodiments will be explained with reference to FIGS.26A to 62B.

At first, in the first production method, as shown in FIG. 26A, thecrosspiece 70 is formed, for example, by means of the film formationmethod at the portions on which the actuator element 14 is not formed,of the first principal surface of the actuator substrate 18. Thematerial quality of the crosspiece 70 is not specifically limited.However, it is preferable to use those having a hard hardness after thehardening. In the case of a resin, for example, it is preferable to usea thermosetting resin (for example, one-component or two-component epoxyresin). The thickness of the crosspiece is about 50 to 100 μm.

The film formation method includes, for example, the screen printingmethod, the photolithography method, and the film lamination method.

The photolithography method includes, for example, a first method inwhich a film 120 to form the crosspiece 70 is exposed and developed sothat the crosspiece 70 is formed as shown in FIGS. 27A to 27C, and asecond method in which a material 124 to form the crosspiece 70 isembedded in an opening 122 a of a mask 122 so that the crosspiece 70 isformed as shown in FIGS. 28A to 28C.

The first method is carried out, for example, in accordance with thefollowing procedure. At first, as shown in FIG. 27A, the film 120 toform the crosspiece 70 is uniformly applied to the entire surface of theactuator substrate 18. Subsequently, as shown in FIG. 27B, the film 120to form the crosspiece 70 is selectively exposed through a mask 130having an opening at the portion for forming the crosspiece 70. Afterthat, as shown in FIG. 27C, the film 120 to form the crosspiece 70 issubjected to development. When the development is performed, then theexposed portion of the film 120 to form the crosspiece 70 remains as thecrosspiece 70, and the non-exposed portion is melted and removed.

Those usable as the method for applying the film for constructing thecrosspiece 70 includes, for example, application by printing,application by spinner, DIP (immersing method), roll coater, and glasspress. It is also possible to apply a photosensitive film having thesame function as that of the photoresist.

On the other hand, the second method is carried out in accordance withthe following procedure. At first, as shown in FIG. 28A, a photoresistmaterial is applied, followed by execution of exposure and developmentto form a mask 122 based on the photoresist on the actuator substrate18. The mask 122 has an opening 122 a at the portion for forming thecrosspiece 70.

Subsequently, as shown in FIG. 28B, a material 124 to form thecrosspiece 70 is embedded in the opening 122 a of the mask 112. Afterthat, as shown in FIG. 28C, the mask 122 is removed. Thus, thecrosspiece 70 is formed on the actuator substrate 18.

In the first method (application method), the selectivity is low for thematerial for the film 120 for constructing the crosspiece 70, because ofthe condition of the exposure. However, in the second method (embeddingmethod), it is unnecessary to consider the exposure or thephotosensitive property. Therefore, the degree of freedom is improvedfor the, selectivity for the material of the film 120 for constructingthe crosspiece 70.

The film lamination method is shown in FIG. 29. In this method, a film(film formed with a material to construct the crosspiece: dry film orthe like) is previously subjected to cutting or stamping to prepare thecrosspiece 70, and then the crosspiece 70 is laminated on the actuatorsubstrate 18, for example, by the aid of an adhesive 132. When thecrosspiece is laminated, for example, the vacuum packaging method or thelaminate press method is used.

In the ceramic sintering method, for example, a portion, which is usedto form a first layer crosspiece 70, is formed on the actuator substrate18, for example, by means of the film formation method, followed bysintering to integrate the actuator substrate 18 and the first layercrosspiece 70 into one unit.

The first production method will be explained again. As shown in FIG.26B, the respective pixel structures 102 are formed on the respectiveactuator elements 14 of the actuator substrate 18, for example, by meansof the film formation method. The various methods as shown in FIGS. 27Ato 29 are adoptable as the film formation method.

As shown in FIG. 26C, before the crosspiece 70 and the pixel structure102 on the actuator substrate 18 are hardened, the optical waveguideplate 12 is pressed against the crosspiece 70 and the pixel structure102 on the actuator substrate 18. The optical waveguide plate 12 and theactuator substrate 18 are pressurized in the directions to make approachto one another. After that, the crosspiece 70 and the pixel structure102 are hardened in this state to complete the device.

In the first production method, the actuator substrate 18 and theoptical waveguide plate 12 are pressurized in the state in which atleast the pixel structure 102 is not hardened. Therefore, the opticalwaveguide plate 12 presses the crosspiece 70 and the pixel structure 102toward the actuator substrate 18 during the pressurizing process. Thepreviously formed crosspiece 70 serves as a spacer, to define thethickness of the pixel structure 102. As a result, when at least thepixel structure 102 is hardened, the upper surface of the crosspiece 70and the upper surface of the pixel structure 102 form a substantiallyidentical surface.

In this embodiment, a material, with which the pixel structure 102 iscontracted upon the hardening of the pixel structure 102, is used as theconstitutive material for the pixel structure 102. By doing so, it ispossible to form a constant gap “g” between the pixel structure 102 andthe optical waveguide plate 12 during the hardening of the crosspiece 70and the pixel structure 102.

Another method is available to form the gap “g”. For example, when theoptical waveguide plate 12 is laminated and pressurized, then the pixelstructure 102 may be heated and expanded, or the actuator element 14 maybe displaced to allow the pixel structure 102 to make contact with theoptical waveguide plate 12. The constant gap “g” is formed between thepixel structure 102 and the optical waveguide plate 12 by thecontraction of the pixel structure 102 or by the displacement reset(restoration) of the actuator element. 14.

Alternatively, it is possible to use the form in which the pixelstructure 102 contacts with the optical waveguide plate 12 in thenatural state. In this case, for example, as shown in FIG. 7,application may be made for the arrangement in which the pixel structure102 makes displacement in the direction to make separation from theoptical waveguide plate 12, concerning the displacement action of theactuator element 14.

The pressurizing method for the actuator substrate 18 and the opticalwaveguide plate 12 includes various loading methods such as the loadingbased on the weight, the vacuum packaging method, the CIP method(hydrostatic pressure loading method), the loading based on the flipchip bonding, the constant value control, and the low pressure pressmethod.

Among them, the vacuum packaging method is shown in FIG. 30. In thismethod, the optical waveguide plate 12 is pressed against the actuatorsubstrate 18, and they are placed in a vacuum packaging bag 140 to applythe vacuum to the bag 140. Thus, the actuator substrate 18 and theoptical waveguide plate 12 are pressurized to one another. In thismethod, in order to suppress the generation of bubbles, it is preferablethat an antifoaming agent is added to the adhesive and the pixelstructure, and an antifoaming treatment is applied before the hardeningprocess.

In the vacuum packaging method shown in FIG. 30 and in the CIP method,the actuator substrate 18 and the optical waveguide plate 12 can beuniformly pressurized even when the actuator substrate 18 involves anywarpage or waviness. Accordingly, the optical waveguide plate 12 and theactuator substrate 18 are adapted to one another. Therefore, it ispossible to form a constant gap “g” between all of the pixel structures102 and the optical waveguide plate 12. It is noted that the vacuumpackaging method may be combined with the CIP method.

The low pressure press method is shown in FIG. 31. In this method, theoptical waveguide plate 12 is pressed against the actuator substrate 18,and they are placed between an upper die 142 and the lower die 144 topress them at a low pressure. In this method, the actuator substrate 18is applied with a small stress. Therefore, the actuator element 14 canbe prevented from damage or the like.

The method, which uses the loading based on the flip chip bonding, ispreferably used, because it is possible to effect the position control,the pressurizing control, and the heating.

Next, the second production method will be explained with reference toFIGS. 32A to 32D. In the second production method, the pixel structure102 and the crosspiece 70 are formed on the optical waveguide plate 12,and the actuator substrate 18 is laminated and pressurized.

At first, as shown in FIG. 32A, the plurality of crosspieces 70 areformed, for example, by means of the film formation method at theportions other than the portions corresponding to the large number ofpixels, of the optical waveguide plate 12. After that, as shown in FIG.32B, the pixel structures 102 are formed, for example, by means of thefilm formation method at the portions corresponding to the large numberof pixels, of the optical waveguide plate 12.

As shown in FIG. 32C, an adhesive 150 is applied to the upper surfacesof the actuator elements 14 and the positions corresponding to thecrosspieces 70, of the first principal surface of the actuator substrate18 previously formed with the actuator elements 14 at the portionscorresponding to the pixels.

After that, before the crosspieces 70 and the pixel structures 102 onthe optical waveguide plate 12 are hardened, the first principal surfaceside of the actuator substrate 18 is pressed against the crosspieces 70and the pixel structures 102 on the optical waveguide plate 12. Theoptical waveguide plate 12 and the actuator substrate 18 are pressurizedin the directions to make approach to one another. Subsequently, asshown in FIG. 32D, the crosspieces 70, the pixel structures 102, and theadhesive 150 are hardened in this state to complete the device.

According to the second production method, the pixel structure 102 isdirectly formed on the optical waveguide plate 12. Therefore, thismethod is advantageous in that the area of the pixel (contact area withrespect to the optical waveguide plate 12) is easily defined. It is easyto obtain a uniform brightness for all of the pixels.

Also in this embodiment, in the case of the form in which the pixelstructure 102 contacts with the optical waveguide plate 12 when theactuator element 14 is in the natural state, as shown in FIG. 7,application may be made for the arrangement in which the pixel structure102 makes displacement in the direction to make separation from theoptical waveguide plate 12, concerning the displacement action of theactuator element 14.

When the optical waveguide plate 12 is laminated and pressurized, thenthe pixel structure 102 may be heated and expanded, or the actuatorelement 14 may be displaced to allow the pixel structure 102 to makecontact with the optical waveguide plate 12. By doing so, it is possibleto form a constant gap “g” between the pixel structure 102 and theoptical waveguide plate 12 during the hardening process for thecrosspiece 70 and the pixel structure 102.

Next, the third production method will be explained with reference toFIGS. 33A to 33C. In this third production method, the plate member 200is once laminated on the actuator substrate 18 formed with the pixelstructure 102 and the crosspiece 70 to obtain a substantially identicalsurface for the respective upper surfaces of the pixel structure 102 andthe crosspiece 70. After that, the plate member 200 is removed, and theoptical waveguide plate 12 is laminated.

At first, as shown in FIG. 33A, the crosspiece 70 is formed, forexample, by means of the film formation method at the portion formedwith no actuator element 14, of the first principal surface of theactuator substrate 18.

After that, as shown in FIG. 33B, the pixel structure 102 is formed, forexample, by means of the film formation method on each of the actuatorelements 14 of the actuator substrate 18.

Subsequently, as shown in FIG. 33C, before the crosspiece 70 and thepixel structure 102 on the actuator substrate 18 are hardened, the platemember 200 is pressed against the crosspiece 70 and the pixel structure102 on the actuator substrate 18. The plate member 200 and the actuatorsubstrate 18 are pressurized in the directions to make approach to oneanother. After that, the crosspiece 70 and the pixel structure 102 arehardened in this state.

Those usable as the plate member 200 include, for example, glass,ceramics, and metal. Among them, glass is used especially preferably,because it is easy to obtain a plate member having high surfacesmoothness and appropriate rigidity.

The surface smoothness of the plate member is useful to improve thebrightness of the pixel. Accordingly, those in which Ra<0.1 μm is givenare preferably used. Especially, those in which Ra<0.01 μm is given aremore preferably used.

The rigidity of the plate member is designed such that the pressurizingstep causes no plastic deformation, and the elastic deformation effectsadaptation to any warpage of the actuator substrate. For example, whenglass is used for the plate member, and the vacuum packaging method isapplied as the pressurizing method, then the thickness of the platemember is preferably about 0.5-fold to 10-fold as compared with thethickness of the actuator substrate. Especially preferably, thethickness of the plate member is 1-fold to 5-fold.

On the other hand, when the low pressure press method is used as thepressurizing method, it is preferable that the plate member is thick inthe view of the rigidity and the easiness of handling, because the smallamount of deformation of the plate member is preferred.

As described above, those usable as the pressurizing method for theplate member 200 and the actuator substrate 18 include the variousloading methods such as the loading based on the weight, the vacuumpackaging method, the CIP method (hydrostatic pressure loading method),the loading based on the flip chip bonding, the constant value control,and the low pressure press method.

When the plate member 200 is laminated on the actuator substrate 18followed by the pressurizing process, the crosspiece 70, which has beenformed on the actuator substrate 18, serves as a spacer to define thedistance between the actuator substrate 18 and the plate member 200. Thecrosspiece 70 and the pixel structure 102 are hardened after thepressurizing or in the pressurized state. Therefore, the defineddistance corresponds to the distance between the actuator substrate 18and the optical waveguide plate 12.

In this embodiment, a material, with which the pixel structure 102 iscontracted during the hardening of the pixel structure 102, is used asthe constitutive material for the pixel structure 102. By doing so, itis possible to form a constant gap “g” between the pixel structure 102and the plate member 200 during the hardening for the crosspiece 70 andthe pixel structure 102. This fact is equivalent to the fact that theconstant gap “g” is formed between the pixel structure 102 and theoptical waveguide plate 12.

When the material, with which the pixel structure 102 is contractedduring the hardening of the pixel structure 102, is not used, the gap“g” may be formed as follows between the pixel structure 102 and theplate member 200 during the hardening of the crosspiece 70 and the pixelstructure 102. That is, for example, when the plate member 200 islaminated and pressurized, then the pixel structure 102 may be heatedand expanded, or the actuator element 14 may be displaced to allow thepixel structure 102 to make contact with the plate member 200. Theconstant gap “g” is formed between the pixel structure 102 and the platemember 200 owing to the contraction of the pixel structure 102 or thedisplacement reset (restoration) of the actuator element 14, during thehardening of the crosspiece 70 and the pixel structure 102 effectedthereafter.

Alternatively, when the pixel structure 102 contacts with the opticalwaveguide plate 12 in the natural state, for example, as shown in FIG.7, application may be made for the arrangement in which the pixelstructure 102 makes displacement in the direction to make separationfrom the optical waveguide plate 12, concerning the displacement actionof the actuator element 14.

When a smooth plate member is used as the plate member 200, a smoothsurface, which is equivalent to the surface of the plate member 200, isformed on the surface of the pixel structure 102. The excellentsmoothness is useful to improve the brightness upon light emissioneffected by the pixel.

As shown in FIG. 34, when a plate member, which has a plurality ofprojections 202 at the corresponding portions 10 with respect to thepixel structure 102, is used as the plate member 200, recesses 110,which correspond to the projections 202, are formed on the surface ofthe pixel structure 102 during the pressurizing process for the platemember 200 and the actuator substrate 18. Thus, it is possible toproduce the display device Dc according to the third embodiment shown inFIG. 21.

As shown in FIG. 35, when a plate member, which has a projection 204 ateach of the portions corresponding to the circumferential edge of thepixel structure 102, is used as the plate member 200, the step 112,which corresponds to the projection 204, is formed at thecircumferential edge of the pixel structure 102 during the pressurizingprocess for the plate member 200 and the actuator substrate 18. Thus, itis possible to produce the display device Dd according to the fourthembodiment shown in FIG. 22.

As shown in FIG. 36, when a plate member, which has a convexconfiguration 206 at each of the portions corresponding to the pixelstructure 102, is used as the plate member 200, the concaveconfiguration 114, which corresponds to the convex configuration 206, isformed on the surface of the pixel structure 102 during the pressurizingprocess for the plate member 200 and the actuator substrate 18. Thus, itis possible to produce the display device De according to the fifthembodiment shown in FIG. 23.

As shown in FIG. 37, a plate member, which has a plurality ofprojections 208 at the portions corresponding to the crosspieces 70respectively, is used as the plate member 200, the upper end of thepixel structure 102 is formed to be higher than the upper end of thecrosspiece 70 during the pressurizing process for the plate member 200and the actuator substrate 18. In this arrangement, the contact of thepixel structure 102 with respect to the optical waveguide plate 12 ismade in a more complete manner, for example, in the display device Dashown in FIG. 7 which exhibits the ON state in the natural state. It isa matter of course that this arrangement is also preferably applicableto those having no gap-forming layer 50 concerning the display device Dashown in FIG. 7.

Another effect is also obtained. That is, it is possible to form a thickgap-forming layer 50. Therefore, when the gap-forming layer 50 functionsas a light-absorbing layer, this arrangement is effective to improve theimage quality such as the contrast. Further, it is possible to widen therange of material selection for the gap-forming layer 50. Of course,this arrangement is also applicable to the display device of the type inwhich the pixel structure 102 is separated from the optical waveguideplate 12 in the natural state.

On the other hand, when a plate member, which has a plurality ofrecesses at the portions corresponding to the crosspieces 70respectively, is utilized as the plate member 200, the upper end of thepixel structure 102 is formed to be lower than the upper end of thecrosspiece 70 during the pressurizing process for the plate member 200and the actuator substrate 18. In this arrangement, a precise gap “g”can be formed even in the case of the form in which the gap-forminglayer 50 is not provided.

The projections 202 of the plate member 200 or the like shown in FIGS.34 to 37 is equivalently applicable to the fourth production method andthe followings as described later on.

After that, as shown in FIG. 38A, the plate member 200 is removed, andthen an adhesive 210 is applied to the upper surface of the crosspiece70 on the actuator substrate 18, for example, by means of the filmformation method.

It is preferable to use an adhesive having high light-absorbingperformance, because it is necessary to suppress the light scattering.For example, it is desirable to use an adhesive added with carbon black,black pigment, or black dye.

As shown in FIG. 38B, before the adhesive 210 is hardened, the opticalwaveguide plate 12 is pressed against the crosspiece 70 on the actuatorsubstrate 18. The optical waveguide plate 12 and the actuator substrate18 are pressurized in the directions to make approach to one another.Subsequently, the adhesive 210 is hardened in this state to complete thedevice.

As described above, those preferably usable as the pressurizing methodfor the optical waveguide plate 12 and the actuator substrate 18 includethe various loading methods such as the loading based on the weight, thevacuum packaging method, the CIP method (hydrostatic pressure loadingmethod), the loading based on the flip chip bonding, the constant valuecontrol, and the low pressure press method.

As described above, it is preferable to use the plate member 200 havingthe projection 202, 204, 206 on the surface, concerning the method forforming the recess 110 or the step 112 on the surface of the pixelstructure 102, or for forming the concave configuration 114 on thesurface of the pixel structure 102. For this purpose, it is preferableto use the method in which the metal film or the resist film is formedin accordance with the ordinary thin film formation method on the platemember 200 composed of glass. This method is advantageous in that thepattern and the height of the projection 202, 204, 206 can be freelychanged. It is preferable that the height of the projection 202, 204,206 is about 0.1 to 2 μm.

Concerning the above, another method, which is based on the planepolishing for the surface of the pixel structure 102 or the surfaceprocessing based on the laser, can be also used as the method forforming the recess 110 or the step 112 on the surface of the pixelstructure 102. The laser processing is not limited to the formation ofthe recess 110 and the step 112, but it also has an effect of surfaceimprovement by the aid of the heating. Further, it is possible toarbitrarily design the processing pattern. Therefore, the laserprocessing is used especially preferably.

On the other hand, the method for forming the concave configuration 114on the surface of the pixel structure 102 is not limited to the methodsdescribed above. Besides, there are a method of heating, and a method ofpreviously applying a voltage to the actuator element 14 during thehardening process for the pixel structure 102. There are a method inwhich the heating is performed during the figuring hardening with theplate member 200, and a method in which the heating is performed afterthe removal of the plate member 200. These methods can be selecteddepending on the material quality of the pixel structure 102. A heatingtemperature of 15° C. to 150° C. is used. Especially, a heatingtemperature of 20° C. to 80° C. is preferably used.

Next, the fourth production method will be explained with reference toFIGS. 39A to 39D. In the fourth production method, the pixel structure102 and the crosspiece 70 are formed on the plate member 200, and theyare hardened respectively. After that, the actuator substrate 18 islaminated. Subsequently, the plate member 200 is removed, and theoptical waveguide plate 12 is laminated.

At first, as shown in FIG. 39A, the crosspiece 70 is formed, forexample, by means of the film formation method at the portions otherthan the portions corresponding to the large number of pixels, of theplate member 200, and then the crosspiece 70 is hardened. Subsequently,as shown in FIG. 39B, the pixel structure 102 is formed, for example, bymeans of the film formation method at the portions corresponding to thelarge number of pixels, of the plate member 200, and then the pixelstructure 102 is hardened.

After that, as shown in FIG. 39C, an adhesive 212 is applied to theupper surface of the actuator element 14 and the position correspondingto the crosspiece 70, of the first principal surface of the actuatorsubstrate 18 previously formed with the actuator elements 14 at thecorresponding portions.

After that, before the adhesive 212 is hardened, the first principalsurface side of the actuator substrate 18 is pressed against thecrosspiece 70 and the pixel structure 102 on the plate member 200. Theplate member 200 and the actuator substrate 18 are pressurized in thedirections to make approach to one another. Subsequently, the adhesive212 is hardened in this state.

After that, as shown in FIG. 39D, the plate member 200 is removed. Atthis point of time, the crosspiece 70 and the pixel structure 102, whichhave been formed on the plate member 200 are transferred to the actuatorsubstrate 18. Therefore, as shown in FIG. 39A, for example, it ispreferable that a releasing agent is applied to the plate member 200before the crosspiece 70 and the pixel structure 102 are formed on theplate member 200, because of the following reason. That is, the pixelstructure 102 and the crosspiece 70 can be smoothly transferred to theactuator substrate 18.

After that, as shown in FIG. 38A, the adhesive 210 is applied, forexample, by means of the film formation method on the upper surface ofthe crosspiece 70 on the actuator substrate 18.

As shown in FIG. 38B, before the adhesive 210 is hardened, the opticalwaveguide plate 12 is pressed against the crosspiece 70 on the actuatorsubstrate 18. The optical waveguide plate 12 and the actuator substrate18 are pressurized to make approach to one another. After that, theadhesive 210 is hardened in this state to complete the device.

The embodiment shown in FIGS. 38A and 38B is illustrative of the case inwhich the optical waveguide plate 12 is directly laminated on the uppersurface of the crosspiece 70. Alternatively, it is also possible toadopt a method shown in FIGS. 40A and 40B.

That is, as shown in FIG. 40A, the adhesive 210 is applied, for example,by means of the film formation method to the upper surface of thecrosspiece 70 on the actuator substrate 18.

As shown in FIG. 40B, the gap-forming layer 50 is previously formed, forexample, by means of the film formation method at the portionscorresponding to the crosspiece, of the optical waveguide plate 12.Before the adhesive 210 is hardened, the optical waveguide plate 12 ispressed against the crosspiece 70 on the actuator substrate 18 (thegap-forming layer 50 is pressed against the crosspiece 70). The opticalwaveguide plate 12 and the actuator substrate 18 are pressurized in thedirections to make approach to one another. After that, the adhesive 210is hardened in this state to complete the device.

As shown in FIGS. 40A and 40B, when the gap-forming layer 50 isprovided, it is easier to obtain the uniform gap “g” for all of thepixels between the pixel structure 102 and the optical waveguide plate12. It is also possible to easily control the size of the gap “g”.

Next, the fifth production method will be explained with reference toFIGS. 41A to 41C. In the fifth production method, the pixel structure102 is formed on the optical waveguide plate 12, and the crosspiece 70is formed on the actuator substrate 18. After that, the opticalwaveguide plate 12 and the actuator substrate 18 are laminated andpressurized.

At first, as shown in FIG. 41A, the pixel structures 102 are formed, forexample, by means of the film formation method at the portionscorresponding to the large number of pixels, of the optical waveguideplate 12. Subsequently, as shown in FIG. 41B, the crosspiece 70 isformed, for example, by means of the film formation method at theportions formed with no actuator element 14, of the first principalsurface of the actuator substrate 18. After that, an adhesive 210 to isapplied, for example, by means of the film formation method to the uppersurface of the crosspiece 70 on the actuator substrate 18.

As shown in FIG. 41C, before the adhesive 210 is hardened, the surfaceof the actuator substrate 18 formed with the crosspiece 70 and thesurface of the optical waveguide plate 12 formed with the pixelstructure 102 are laminated with each other. The optical waveguide plate12 and the actuator substrate 18 are pressurized in the directions tomake approach to one another. After that, the adhesive 210 is hardenedin this state to complete the device.

According to the fifth production method, the formation of the pixelstructure 102 and the formation of the crosspiece 70 can be carried outin the mutually independent steps. Therefore, the range of materialselection is widened concerning the pixel structure 102 and thecrosspiece 70, and it is possible to reduce the production cost and thenumber of production steps. Further, the pixel structure 102 is formedon the optical waveguide plate 12 which has high flatness. Therefore, itis possible to obtain a uniform size of the pixel structure 102.

Next, the sixth production method will be explained with reference toFIGS. 42A to 42C. In the sixth production method, the crosspiece 70 isformed on the optical waveguide plate 12, and the pixel structure 102 isformed, on the actuator substrate 18. After that, the optical waveguideplate 12 and the actuator substrate 18 are laminated and pressurized.

At first, as shown in FIG. 42A, the plurality of crosspieces 70 areformed, for example, by means of the film formation method at theportions other than the portions corresponding to the large number ofpixels, of the optical waveguide plate 12. Subsequently, as shown inFIG. 42B, the pixel structures 102 are formed, for example, by means ofthe film formation method on the actuator elements 14 of the firstprincipal surface of the actuator substrate 18. After that, an adhesive212 is applied, for example, by means of the film formation method tothe upper surfaces of the crosspieces 70 on the optical waveguide plate12. Alternatively, the adhesive 212 is formed, for example, by means ofthe film formation method on the portions formed with no actuatorelement 14, of the first principal surface of the actuator substrate 18.

After that, as shown in FIG. 42C, before the adhesive 212 is hardened,the surface of actuator substrate 18 formed with the pixel structure 102and the surface of the optical waveguide plate 12 formed with thecrosspiece 70 are laminated with each other. The optical waveguide plate12 and the actuator substrate 18 are pressurized in the directions tomake approach to one another. After that, the adhesive 212 is hardenedin this state to complete the device.

Also in the sixth production method, the formation of the pixelstructure 102 and the formation of the crosspiece 70 can be carried outin the mutually independent steps. Therefore, the range of materialselection is widened concerning the pixel structure 102 and thecrosspiece 70, and it is possible to reduce the production cost and thenumber of production steps. Further, the crosspiece 70 is formed on theoptical waveguide plate 12 which has high flatness. Therefore, it ispossible to obtain a strictly uniform size of the crosspiece 70.Furthermore, no obstacle (for example, the crosspiece 70) exists whenthe pixel structure 102 is formed. Therefore, the pixel structure 102can be formed accurately.

Next, the seventh production method will be explained with reference toFIGS. 43A and 43B. In the seventh production method, the pixel structure102 is formed on the actuator substrate 18 which has been previouslyprovided with the crosspiece 70 in the integrated manner. After that,the optical waveguide plate 12 is laminated and pressurized.

At first, as shown in FIG. 43A, the pixel structures 102 are formed onthe respective actuator elements 14 of the actuator substrate 18 whichintegrally includes, the plurality of crosspieces 70 at the portionsother than the actuator elements 14. Subsequently, an adhesive 210 isformed, for example, by means of the film formation method on the uppersurfaces of the crosspieces 70 on the actuator substrate 18.

As shown in FIG. 43B, before the crosspieces 70 and the pixel structures102 on the actuator substrate 18 are hardened, the optical waveguideplate 12 is pressed against the crosspieces 70 and the pixel structures102 on the actuator substrate 18. The optical waveguide plate 12 and theactuator substrate 18 are pressurized in the directions to make approachto one another. After that, the crosspieces 70 and the pixel structures102 are hardened in this state to complete the device.

In the seventh production, method, the actuator substrate 18, whichpreviously has the crosspieces 70 in the integrated manner, is used asthe actuator substrate 18. Therefore, the mechanical strength of theportion of the crosspiece 70 is high. Accordingly, the rigidity of theactuator substrate 18 is enhanced. As a result, for example, when theactuator substrate 18 is carried or stored, the crosspiece 70 can beused to protect the actuator element 14, especially the vibratingsection 22 formed on the actuator substrate 18. The step of hardeningthe crosspiece 70 can be omitted, as compared with the case in which thecrosspiece 70 is formed separately. Thus, it is possible to reduce thenumber production steps.

Next, the eighth production method will be explained with reference toFIGS. 44A to 45B. In the eighth production method, the crosspiece 70 isformed on the actuator substrate 18, and the pixel structure 102 isformed on the plate member 200. The actuator substrate 18 and the platemember 200 are laminated and pressurized. After that, the plate member200 is removed, and the optical waveguide plate 12 is laminated andpressurized.

At first, as shown in FIG. 44A, the pixel structures 102 are formed atthe portions corresponding to the large number of pixels, of the platemember 200. Subsequently, as shown in FIG. 44B, the plurality ofcrosspieces 70 are formed at the portions other than the actuatorelements 14, of the actuator substrate 18.

Subsequently, as shown in FIG. 44C, before the crosspieces 70 and thepixel structures 102 on the actuator substrate 18 are hardened, thesurface of the actuator substrate 18 formed with the crosspieces 70 andthe surface of the plate member 200 formed with the pixel structures 102are laminated with each other. The plate member 200 and the actuatorsubstrate 18 are pressurized in the directions to make approach to oneanother. After that, the crosspieces 70 and the pixel structures 102 arehardened in this state.

After that, as shown in FIG. 45A, the plate member 200 is removed, andthe pixel structures 102 are transferred to the actuator substrate 18.Subsequently, an adhesive 210 is applied, for example, by means of thefilm formation method to the upper surfaces of the crosspieces 70 on theactuator substrate 18.

As shown in FIG. 45B, before the adhesive 210 is hardened, the opticalwaveguide plate 12 is pressed against the crosspieces 70 on the actuatorsubstrate 18. The optical waveguide plate 12 and the actuator substrate18 are pressurized in the directions to make approach to one another.After that, the adhesive 210 is hardened in this state to complete thedevice.

In this embodiment, the formation of the pixel structure 102 and theformation of the crosspiece 70 can be carried out in the mutuallyindependent steps. Therefore, the range of material selection is widenedconcerning the pixel structure 102 and the crosspiece 70, and it ispossible to reduce the production cost and the number of productionsteps. Further, the pixel structure 102 is formed on the plate member200 which has high flatness. Therefore, it is possible to obtain auniform size of the pixel structure 102.

Next, the ninth production method will be explained with reference toFIGS. 46A to 47B. In the ninth production method, the pixel structure102 is formed on the actuator substrate 18, and the crosspiece 70 isformed on the plate member 20. The actuator substrate 18 and the platemember 200 are laminated and pressurized. After that, the plate member200 is removed, and the optical waveguide plate 12 is laminated andpressurized.

At first, as shown in FIG. 46A, the crosspieces 70 are formed at theportions other than the portions corresponding to the large number ofpixels, of the plate member 200. Subsequently, as shown in FIG. 46B, thepixel structures 102 are formed on the respective actuator elements 14of the actuator substrate 18. After that, an adhesive 212 is formed, forexample, by means of the film formation method on the lower surfaces ofthe crosspieces 70 formed on the plate member 200. The adhesive 212 maybe applied to the portions other than the actuator elements 14 of theactuator substrate 18, not to the upper surfaces of the crosspieces 70.

Subsequently, as shown in FIG. 46C, before the pixel structures 102 onthe actuator substrate 18 are hardened, the surface of the actuatorsubstrate 18 formed with the pixel structures 102 and the surface of theplate member 200 formed with the crosspieces 70 are laminated with eachother. The plate member 200 and the actuator substrate 18 arepressurized in the directions to make approach to one another. Afterthat, the pixel structures 102 are hardened in this state.

After that, as shown in FIG. 47A, the plate member 200 is removed, andthe crosspieces 70 are transferred to the actuator substrate 18.Subsequently, an adhesive 210 is applied, for example, by means of thefilm formation method to the upper surfaces of the crosspieces 70 on theactuator substrate 18.

As shown in FIG. 47B, before the adhesive 210 is hardened, the opticalwaveguide plate 12 is pressed against the crosspieces 70 on the actuatorsubstrate 18. The optical waveguide plate 12 and the actuator substrate18 are pressurized in the directions to make approach to one another.After that, the adhesive 210 is hardened in this state to complete thedevice.

Also in this embodiment, the formation of the pixel structure 102 andthe formation of the crosspiece 70 can be carried out in the mutuallyindependent steps. Therefore, the range of material selection is widenedconcerning the pixel structure 102 and the crosspiece 70, and it ispossible to reduce the production cost and the number of productionsteps. Further, the crosspiece 70 is formed on the plate member 200which has high flatness. Therefore, it is possible to obtain a strictlyuniform size of the crosspiece 70. Furthermore, no obstacle (forexample, the crosspiece 70) exists when the pixel structure 102 isformed. Therefore, the pixel structure 102 can be formed accurately.

Especially, the ninth production method is preferably used to form thecrosspiece 70 having the stripe-shaped opening 220 as shown in FIG. 13,and the line-shaped crosspiece 70 as shown in FIG. 14. That is, the filmis punched and processed to form the stripe-shaped opening 220, or thefilm is finely cut into the line-shaped configuration.

Subsequently, as shown in FIG. 48, the crosspiece 70 composed of thefilm is laminated on the plate member 200 by utilizing the surfacetension of the liquid (for example, water). After that, the processleads to the step shown in FIG. 46A. In this case, the crosspiece 70 ismerely affixed to the plate member 200 by the aid of only the surfacetension of the liquid. Therefore, it is easy to remove the plate member200 thereafter.

Next, the tenth production method will be explained with reference toFIGS. 49A to 50B. In the tenth production method, the pixel structure102 is formed on the actuator substrate 18. After that, the actuatorsubstrate 18 is laminated with the jig 234 including the large number ofsize-defining members 232 provided on the plate member 230, and they arepressurized. Thus, the size of the pixel structure 102 is defined.Subsequently, the jig 234 is removed, and the crosspiece 70 is formed onthe actuator substrate 18. After that, the optical waveguide plate 12 islaminated and pressurized.

At first, as shown in FIG. 49A, the pixel structures 102 are formed onthe respective actuator elements 14 of the actuator substrate 18.

After that, as shown in FIG. 49B, the jig 234 is prepared, whichincludes, on one surface of the plate member 230, the large number ofsize-defining members 232 having approximately the same height as thatof the crosspieces 70 to be formed on the actuator substrate 18. Thesurface of the jig 234 formed with the size-defining members 232 and thesurface of the actuator substrate 18 formed with the pixel structures102 are laminated with each other. The jig 234 and the actuatorsubstrate 18 are pressurized in the directions to make approach to oneanother. After that, the pixel structures 102 are hardened in thisstate.

Subsequently, as shown in FIG. 49C, the jig 234 is removed. After that,as shown in FIG. 50A, the plurality of crosspieces 70 are formed at theportions other than the actuator elements 14, of the actuator substrate18. Subsequently, an adhesive 210 is applied, for example, by means ofthe film formation method to the upper surfaces of the crosspieces 70 onthe actuator substrate 18.

As shown in FIG. 50B, before the adhesive 210 is hardened, the opticalwaveguide plate 12 is pressed against the crosspieces 70 on the actuatorsubstrate 18. The optical waveguide plate 12 and the actuator substrate18 are pressurized in the directions to make approach to one another.Subsequently, the adhesive 210 is hardened in this state to complete thedevice.

In the tenth production method, for example, when the jig 234 is formedby using a member having rigidity such as metal, it is possible toreduce the waviness of the actuator substrate 18 formed with the pixelstructures 102, by laminating and pressurizing the jig 234 and theactuator substrate 18. It is possible to form the crosspiece 70 highlyaccurately in the step of forming the crosspiece 70 performedthereafter.

Next, the eleventh production method will be explained with reference toFIGS. 51A to 52B. In the eleventh production method, the pixelstructures 102 are formed on the actuator substrate 18, and then theactuator substrate 18 and the jig 234 including, on the plate member230, the large number of size-defining members 232 are laminated andpressurized with each other. Thus, the size of the pixel structure 102is defined. After the jig 234 is removed, the crosspieces 70 are formedon the optical waveguide plate 12. The optical waveguide plate 12 andthe actuator substrate 18 are laminated with each other.

At first, as shown in FIG. 51A, the pixel structures 102 are formed onthe respective actuator elements 14 of the actuator substrate 18.

After that, as shown in FIG. 51B, the jig 234 is prepared, whichincludes the large number of size-defining members 232 havingapproximately the same height as that of the crosspieces 70 to be formedon the actuator substrate 18, the size-defining members 232 being formedon one surface of the plate member 230. The surface of the jig 234formed with the size-defining members 232 and the surface of theactuator substrate 18 formed with the pixel structures 102 are laminatedwith each other. The jig 234 and the actuator substrate 18 arepressurized in the directions to make approach to one another. Afterthat, the pixel structures 102 are hardened in this state.

Subsequently, as shown in FIG. 51C, the jig 234 is removed, and then thecrosspieces 70 are formed at the portions other than the portionscorresponding to the large number of pixels, of the optical waveguideplate 12 as shown in FIG. 52A. After that, an adhesive 212 is applied,for example, by means of the film formation method to the lower surfacesof the crosspieces 70 on the plate member 70.

As shown in FIG. 52B, before the adhesive 212 is hardened, the surfaceof the actuator substrate 18 formed with the pixel structures 102 andthe surface of the optical waveguide plate 12 formed with thecrosspieces 70 are laminated with each other. The optical waveguideplate 12 and the actuator substrate 18 are pressurized in the directionsto make approach to one another. After that, the adhesive 212 ishardened in this state to complete the device.

Also in the eleventh production method, for example, when the jig 234 isformed by using a member having rigidity such as metal, it is possibleto reduce the waviness of the actuator substrate 18 formed with thepixel structures 102, by laminating and pressurizing the jig 234 and theactuator substrate 18. It is possible to carry out the lamination withthe optical waveguide plate 12 highly accurately performed thereafter.

The gap-forming layer 50 may be provided on the optical waveguide plate12. In this arrangement, the gap amount can be easily adjusted bycontrolling the difference between the height, of the crosspiece 70 andthe height of the size-defining member 232.

Next, the twelfth production method will be explained with reference toFIGS. 53A to 54B. In the twelfth production method, the pixel structure102 is formed on the actuator substrate 18, and the crosspiece 70 isformed on the jig 234 including, on the plate member 230, the largenumber of size-defining members 232. The actuator substrate 18 and thejig 234 are laminated and pressurized so that the size of the crosspiece70 and the pixel structure 102 is defined. After that, the jig 234 isremoved. The crosspiece 70 is transferred to the actuator substrate 18,and then the optical waveguide plate 12 is laminated.

At first, as shown in FIG. 53A, the plurality of crosspieces 70 areformed at the portions formed with no size-defining member 232, of thesurface of the jig 324 formed with the size-defining members 232, theportions being other than the portions corresponding to the large numberof pixels. After that, an adhesive 212 is applied, for example, by meansof the film formation method to the lower surfaces of the crosspieces 70formed on the jig 234.

The pixel structures 102 are formed on the respective actuator elements14 of the actuator substrate 18.

Subsequently, as shown in FIG. 53B, before the pixel structures 102 onthe actuator substrate 18 are hardened, the surface of the actuatorsubstrate 18 formed with the pixel structures 102 and the surface of thejig 234 formed with the crosspieces are laminated with each other. Thejig 234 and the actuator substrate 18 are pressurized in the directionsto make approach to one another, and then the pixel structures 102 arehardened in this state.

After that, as shown in FIG. 53C, the jig 234 is removed, and thecrosspieces 70 are transferred to the actuator substrate. Subsequently,as shown in FIG. 54A, the adhesive 210 is applied, for example, by meansof the film formation method to the upper surfaces of the crosspieces 70on the actuator substrate 18.

As shown in FIG. 54B, before the adhesive 210 is hardened, the opticalwaveguide plate 12 is pressed against the crosspieces 70 on the actuatorsubstrate 18. The optical waveguide plate 12 and the actuator substrate18 are pressurized in the directions to make approach to one another.After that, the adhesive 210 is hardened in this state to complete thedevice.

Also in this embodiment, for example, when the jig 234 is formed byusing a member having rigidity such as metal, it is possible to reducethe waviness of the actuator substrate 18 formed with the pixel,structures 102, by laminating and pressurizing the jig 234 and theactuator substrate 18. It is possible to form the crosspiece 70 and thepixel structure 102 highly accurately.

Next, the thirteenth production method will be explained with referenceto FIGS. 55A to 56B. In the thirteenth embodiment, the pixel structure102 and the crosspiece 70 are formed on the actuator substrate 18. Theactuator substrate 18 and the jig 234 provided with the large number ofsize-defining members 232 on the plate member 230 are laminated andpressurized. Thus, the size of the crosspiece 70 and the pixel structure102 is defined. After that, the jig 234 is removed, and the opticalwaveguide plate 12 is laminated.

At first, as shown in FIG. 55A, the crosspieces 70 are formed, forexample, by means of the film formation method at the portions formedwith no actuator element 14, of the first principal surface of theactuator substrate 18. The pixel structures 102 are formed, for example,by means of the film formation method on the respective actuatorelements 14 of the actuator substrate 18.

After that, as shown in FIG. 55B, before the crosspieces 70 and thepixel structures 102 on the actuator substrate 18 are hardened, the jig234 is pressed against the crosspieces 70 and the pixel structures 102on the actuator substrate 18. The jig and the actuator substrate 18 arepressurized in the directions to make approach to one another. Afterthat, the crosspieces 70 and the pixel structures 102 are hardened inthis state.

Subsequently, as shown in FIG. 55C, the jig 234 is removed. After that,as shown in FIG. 56A, an adhesive 210 is applied, for example, by meansof the film formation method to the upper surfaces of the crosspieces 70on the actuator substrate 18.

As shown in FIG. 56B, before the adhesive 210 is hardened, the opticalwaveguide plate 12 is pressed against the crosspieces 70 on the actuatorsubstrate 18. The optical waveguide plate 12 and the actuator substrate18 are pressurized in the directions to make approach to one another.After that, the adhesive 210 is hardened in this state to complete thedevice.

Also in this embodiment, for example, when the jig 234 is formed byusing a member having rigidity such as metal, it is possible to reducethe waviness of the actuator substrate 18 formed with the pixelstructures 102 and the crosspieces 70, by laminating and pressurizingthe jig 234 and the actuator substrate 18. It is possible to form thecrosspiece 70 and the pixel structure 102 highly accurately.

Next, the fourteenth production method will be explained with referenceto FIGS. 57A to 58B. In the fourteenth production method, thecrosspieces 70 are formed on the actuator substrate 18. The pixelstructures 102 are formed on the jig including, on the plate member 230,the large number of size-defining members 232. The actuator substrate 18and the jig 234 are laminated and pressurized. Thus, the size of, thecrosspiece 70 and the pixel structure 102 is defined. After that, thejig 234 is removed, and the pixel structure 102 are transferred to theactuator substrate 18. Subsequently, the optical waveguide plate 12 islaminated.

At first, as shown in FIG. 57A, the pixel structures 102 are formed atthe portions corresponding to the large number of pixels, the portionsbeing formed with no size-defining member 232, of the surface of the jig234 formed with the size-defining members 232. The plurality ofcrosspieces 70 are formed at the portions other than the actuatorelements 14 of the actuator substrate 18.

After that, as shown in FIG. 57B, before the crosspieces 70 formed onthe actuator substrate 18 and the pixel structures 102 formed on the jig234 are hardened, the surface of the jig 234 formed with the pixelstructures 102 and the surface of the actuator substrate 18 formed withthe crosspieces 70 are laminated with each other. The jig 234 and theactuator substrate 18 are pressurized in the directions to make approachto one another. Subsequently, the crosspieces 70 and the pixelstructures 102 are hardened in this state.

After that, as shown in FIG. 57C, the jig 234 is removed, and the pixelstructures 102 are transferred to the actuator substrate 18.Subsequently, as shown in FIG. 58A, an adhesive 210 is applied, forexample, by means of the film formation method to the upper surfaces ofthe crosspieces 70 on the actuator substrate 18.

As shown in FIG. 58B, before the adhesive 210 is hardened, the opticalwaveguide plate 12 is pressed against the crosspieces 70 on the actuatorsubstrate 18. The optical waveguide plate 12 and the actuator substrate18 are pressurized in the directions to make approach to one another.After that, the adhesive 210 is hardened in this state to complete thedevice.

Also in this embodiment, for example, when the jig 234 is formed byusing a member having rigidity such as metal, it is possible to reducethe waviness of the actuator substrate 18 formed with the pixelstructures 102, by laminating and pressurizing the jig 234 and theactuator substrate 18. It is possible to form the crosspiece 70 and thepixel structure 102 highly accurately.

Next, the fifteenth production method will be explained with referenceto FIGS. 59A to 60B. In the fifteenth production method, the crosspieces70 and the pixel structures 102 are formed on the jig 234 including, onthe plate member 230, the large number of size-defining members 232. Thejig 234 and the actuator substrate 18 are laminated and pressurized witheach other. Thus, the size of the crosspiece 70 and the pixel structure102 is defined. After that, the jig 234 is removed, and the crosspieces70 and the pixel structures 102 are transferred to the actuatorsubstrate 18. Subsequently, the optical waveguide plate 12 is laminated.

At first, as shown in FIG. 59A, the plurality of crosspieces 70 areformed at the portions formed with no size-defining member 232 of thesurface the jig 234 formed with the size-defining members 232, theportions being other than the portions corresponding to the large numberof pixels. The pixel structures 102 are formed at the portions formedwith no size-defining member 232, of the surface of the jig 234 formedwith the size-defining members 232, the portions corresponding to thelarge number of pixels.

After that, as shown in FIG. 59B, before the crosspieces 70 and thepixel structures 102 formed on the jig 234 are hardened, the jig 234 andthe actuator substrate 18 are laminated with each other. The jig 234 andthe actuator substrate 18 are pressurized in the directions to makeapproach to one another. After that, the crosspieces 70 and the pixelstructures 102 are hardened in this state.

Subsequently, as shown in FIG. 59C, the jig 234 is removed, and thecrosspieces and the pixel structures 102 are transferred to the actuatorsubstrate 18. After that, as shown in FIG. 60A, an adhesive 210 isapplied, for example, by means of the film formation method to the uppersurfaces of the actuator substrate 18.

As shown in FIG. 60B, before the adhesive 210 is hardened, the opticalwaveguide plate 12 is pressed against the crosspieces 70 on the actuatorsubstrate 18. The optical waveguide plate 12, and the actuator substrate18 are pressurized in the directions to make approach to one another.After that, the adhesive 210 is hardened in this state to complete thedevice.

Also in this embodiment, for example, when the jig 234 is formed byusing a member having rigidity such as metal, it is possible to reducethe waviness of the actuator substrate 18 by laminating and pressurizingthe jig 234 and the actuator substrate 18. It is possible to transferand form the crosspiece 70 and the pixel structure 102 highly accuratelyon the actuator substrate 18.

Next, the sixteenth production method will be explained with referenceto FIGS. 61A to 62B. In the sixteenth production method, the pixelstructures 102 are formed on the actuator substrate 18 which includesthe crosspieces 70 in the integrated manner. After that, the platemember 200 is laminated on the actuator substrate 18. Subsequently, theplate member 200 is removed, and the optical waveguide plate 12 islaminated.

At first, as shown in FIG. 61A, the pixel structures 102 are formed onthe respective actuator elements 14 of the actuator substrate 18 whichintegrally includes the plurality of crosspieces 70 at the portionsother than the actuator elements 14.

After that, as shown in FIG. 61B, before the pixel structures 102 on theactuator substrate 18 are hardened, the plate member 200 is pressedagainst the crosspieces 70 and the pixel structures 102 on the actuatorsubstrate 18. The plate member 200 and the actuator substrate 18 arepressurized in the directions to make approach to one another. Afterthat, the pixel structures 102 are hardened in this state.

Subsequently, as shown in FIG. 62A, after the plate member 200 isremoved, an adhesive 210 is applied, for example, by means of the filmformation method to the upper surfaces of the crosspieces 70 on theactuator substrate 18.

As shown in FIG. 62B, before the adhesive is hardened, the opticalwaveguide plate 12 is pressed against the crosspieces 70 on the actuatorsubstrate 18. The optical waveguide plate 12 and the actuator substrate18 are pressurized in the directions to make approach to one another.After that, the adhesive 210 is hardened in this state to complete thedevice.

In this embodiment, the actuator substrate 18, which previously has thecrosspieces 70 in the integrated manner, is used as the actuatorsubstrate 18. Therefore, for example, when the actuator substrate 18 iscarried or stored, the crosspieces 70 can be used to protect theactuator elements 14 formed on the actuator substrate 18. Further, thestep of hardening the crosspiece 70 can be omitted, as compared with thecase in which the crosspiece 70 is separately formed. Accordingly, it ispossible to reduce the number of production steps.

In the respective embodiments described above, it is also possiblethat-the crosspiece 70 has the multiple layered structure. In thisarrangement, the crosspiece 70 having the multiple layered structure canbe formed by using the film formation method. In addition thereto, forexample, the crosspiece having the multiple layered structure can bealso formed in accordance with a method in which, for example, theceramic sintering method and the film formation method are combined witheach other. The crosspiece 70 having the multiple layered structure isadvantageous to adjust the amount of gap.

Further, for example, when the adhesive is applied onto the crosspiece70, for example, an adhesive having light-absorbing property is used. Bydoing so, the adhesive may be allowed to play the role of thegap-forming layer 50. When the adhesive is applied onto the pixelstructure 102 or the actuator element 14, for example, an adhesivehaving light-reflective property is used. By doing so, the adhesive maybe allowed to function as a part of the pixel structure 102.

It is a matter of course that the display device and the method forproducing the same according to the present invention are not limited tothe embodiments described above, which may be embodied in other variousforms without deviating from the gist or essential characteristic of thepresent invention.

INDUSTRIAL APPLICABILITY

As explained above, according to the display device and the method forproducing the same concerning the present invention, it is possible toobtain the following effects.

(1) The clearance (gap) between the optical waveguide plate and thepixel structure can be easily formed, and it can be formed uniformly forall of the pixels.

(2) The size of the gap can be easily controlled.

(3) The adhesion of the pixel structure to the optical waveguide platecan be avoided, and it is possible to effectively realize the highresponse speed.

(4) The contact surface of the pixel structure (contact surface withrespect to the optical waveguide plate) can be formed to be smooth sothat the light is efficiently introduced into the pixel structure whenthe predetermined pixel structure contacts with the optical waveguideplate.

(5) It is possible to ensure the response speed of the pixel.

(6) it is possible to obtain the uniform brightness for all of thepixels.

(7) it is possible to improve the brightness of the pixel.

What is claimed is:
 1. A display device comprising: an optical waveguideplate for introducing light thereinto; an actuator substitute providedopposingly to one plate surface of said optical waveguide plate, saidactuator substrate comprising a plurality of discrete actuator elementsfixed thereto, said actuator elements corresponding to a large number ofpixels; a pixel structure formed on each of said actuator elements ofsaid actuator substrate; and a crosspiece formed at a portion other thansaid pixel structure between said optical waveguide plate and saidactuator substrate.
 2. The display device according to claim 1, whereinsaid actuator element includes a shape-retaining layer, an operatingsection having at least a pair of electrodes formed on saidshape-retaining layer, a vibrating section for supporting said operatingsection, and a fixed section for supporting said vibrating section in avibrating manner.
 3. The display device according to claim 1, whereinsaid crosspiece is secured to said optical waveguide plate.
 4. Thedisplay device according to claim 1, wherein a gap-forming layer isprovided between said optical waveguide plate and said crosspiece. 5.The display device according to claim 1, wherein said crosspiece isformed at portions around four corners of each said pixel structure. 6.The display device according to claim 1, wherein said crosspiece has awindow for surrounding at least one pixel structure.
 7. The displaydevice according to claim 1, wherein said crosspiece includes astripe-shaped opening which extends along a direction of an array ofsaid pixel structures and which surrounds said array of said pixelstructures.
 8. The display device according to claim 1, wherein saidcrosspiece is formed to have a line-shaped configuration which extendsalong a direction of an array of said pixel structures.
 9. The displaydevice according to claim 1, wherein said crosspiece is farmedintegrally with said actuator substrate.
 10. The display deviceaccording to claim 1, wherein said crosspiece is constructed by a wiremember which extends along a direction of an array of said pixelstructures.
 11. The display device according to claim 1, wherein arecess is formed on a surface of said pixel structure.
 12. The displaydevice according to claim 1, wherein a step is formed on a surface ofsaid pixel structure.
 13. The display device according to claim 1,wherein a surface of said pixel structure has a concave configuration.14. A method for producing a display device, comprising: acrosspiece-forming step of forming a plurality of crosspieces atportions other than actuator elements, of an actuator substrate arrangedwith said actuator elements corresponding to a large number of pixels; apixel-forming step of forming pixel structures on said respectiveactuator elements on said actuator substrate; and a pressurizing step oflaminating and pressurizing an optical waveguide plate in a state inwhich at least said pixel structure are not hardened, and then hardeningat least said pixel structures.
 15. A method for producing a displaydevice, comprising: a crosspiece-forming step of forming a plurality ofcrosspieces at portions other than portions corresponding to a largenumber of actuator elements, of an optical waveguide plate; apixel-forming step of fanning pixel structures at portions correspondingto a large number of pixels, of said optical waveguide plate; and apressurizing step of laminating an actuator substrate arranged withactuator elements of a number corresponding to said large number ofpixels, on said crosspieces and said pixel structures, and pressurizingsaid optical waveguide plate and said actuator substrate directions tomake approach to one another.
 16. A method for producing a displaydevice, comprising: a crosspiece-forming step of forming a plurality ofcrosspieces at portions other than actuator elements, of an actuatorsubstrate arranged with said actuator elements corresponding to a largenumber of pixels; a pixel-forming step of forming pixel structures atportions corresponding to said large number of pixels, of an opticalwaveguide plate; and a pressurizing step of laminating a surface of saidactuator substrate formed with said crosspieces and a sure of saidoptical waveguide plate formed with said pixel structures with eachother, and pressuring said optical waveguide plate and said actuatorsubstrate in directions to make approach to one another.
 17. A methodfor producing a display device, comprising: a crosspiece-forming step offorming a plurality of crosspieces at portions other than portionscorresponding to a large number of actuator elements, of an opticalwaveguide plate; a pixel-forming step of forming pixel structures onrespective actuator elements of an actuator substrate arranged with saidactuator elements of a number corresponding to said large number ofpixels; and a pressurizing step of laminating a surface of said actuatorsubstrate formed with said pixel structures and a surface of saidoptical waveguide plate formed with said crosspieces with each other,and pressurizing said optical waveguide plate and said actuatorsubstrate in directions to make approach to one another.
 18. A methodfor producing a display device, comprising: a pixel-forming step offorming pixel structure on respective actuator elements of an actuatorsubstrate arranged with said actuator elements of a number correspondingto a large number of pixels and integrally having a plurality ofcrosspieces at portions other than said actuator elements; and apressurizing step of laminating and pressurizing an optical waveguideplate in a state in which at least said pixel structures are nothardened, and then hardening at least said pixel structures.
 19. Amethod for producing a display device, comprising: a crosspiece-formingstep of forming a plurality of crosspieces at portions other thanactuator elements, of an actuator substrate arranged with said actuatorelements of a number corresponding to a large number of pixels; apixel-forming step of forming pixel structures on said respectiveactuator elements of said actuator substrate; a first laminating step oflaminating a plate member in a state in which at least said pixelstructures are not hardened; a pressurizing step of pressurizing saidactuator substrate and said plate member in directions to make approachto one another, and then hardening at least said pixel structures; and asecond laminating step of removing said plate member, and thenlaminating an optical waveguide plate at least on said crosspieces. 20.A method for producing a display device, comprising: acrosspiece-forming step of forming a plurality of crosspieces atportions other than portions corresponding to a large number of pixels,of a plate member; a pixel-forming step of forming pixel structures atsaid portions corresponding to said large number of pixels, of saidplate member; a first laminating step of laminating an actuatorsubstrate arranged with actuator elements of a number corresponding tosaid large number of pixels on said crosspieces and said pixelstructures; a pressurizing step of pressurizing said plate member andsaid actuator substrate in directions to make approach to one another;and a second laminating step of removing said plate member to transfersaid crosspieces and said pixel structures to said actuator substrate,and then laminating an optical waveguide plate on at least saidcrosspieces.
 21. A method for producing a display device, comprising: acrosspiece-forming step of forming a plurality of crosspieces atportions other than actuator elements, of an actuator substrate arrangedwith said elements of a number corresponding to a large number ofpixels; a pixel-forming step of forming pixel structures at portionscorresponding to said large number of pixels, of a plate member; a firstlaminating step of laminating a surface of said actuator substrateformed with said crosspieces and surface of said plate member formedwith said pixel structures with each other; a pressurizing step ofpressurizing said plate member and said actuator substrate in directionsto make approach to one another; and a second laminating step ofremoving said plate member to transfer said pixel structures to saidactuator substrate, and then laminating an optical waveguide plate on atleast said crosspieces.
 22. A method for producing a display device,comprising: a pixel-forming step of forming pixel structures onrespective actuator elements of an actuator substrate arranged with saidactuator elements of a number corresponding to a large number of pixels;a crosspiece-forming step of forming a plurality of crosspieces atportions other than portions corresponding to said large number ofpixels, of a plate member; a first laminating step of laminating asurface of said actuator substrate formed with said pixel structures anda surface of said plate member formed with said crosspieces with eachother; a pressurizing step of pressurizing said plate member and saidactuator substrate in directions to make approach to one another; and asecond laminating step of removing said plate member to transfer saidcrosspieces to said actuator substrate, and then laminating an opticalwaveguide plate on at least said crosspieces.
 23. A method for producinga display device, comprising: a pixel-forming step of forming pixelstructures on respective actuator elements of an actuator substratearranged with said actuator elements of a number corresponding to alarge number of pixels and integrally having a plurality of crosspiecesat portions other than said actuator element; a first laminating step oflaminating a plate member in a state in which at least said pixelstructures are not hardened; a pressing step of pressurizing saidactuator substrate and said plate member in directions to make approachto one another, and then hardening at least said pixel structures; and asecond laminating step of removing said plate member, and thenlaminating an optical waveguide plate on at least said crosspieces. 24.A method for producing a display device, comprising: a pixel-formingstep of forming pixel structures on respective actuator elements of anactuator substrate arranged with said actuator elements of a numbercorresponding to a large number of pixels; a first laminating step ofusing a jig including, on one surface of a plate member, a large numberof size defining members formed to have substantially the same height asthat of crosspieces to be formed on said actuator substrate to laminatea surface of said jig formed with said size-defining members and asurface of said actuator substrate formed with said pixel structureswith each other; a pressurizing step of pressurizing said jig and saidactuator substrate in directions to make approach to one another; acrosspiece-forming step of removing said jig, and then forming saidplurality of crosspieces at portions other than said actuator sections,of said actuator substrate; and a second laminating step of laminatingan optical waveguide plate on at least said crosspieces on said actuatorsubstrate.
 25. A method for producing a display device, comprising: apixel-forming step of forming pixel structures on respective actuatorelements of an actuator substrate arranged with said actuator elementsof a number corresponding to a large number of pixels; a firstlaminating step of using a jig including, on one surface of a platemember, a large number of size-defining members formed to havesubstantially the same height as that of crosspieces to be formed onsaid actuator substrate to laminate a surface of said jig formed withsaid size-defining members and a surface of said actuator substrateformed with said pixel structures with each other; a pressurizing stepof pressurizing said jig and said actuator substrate in directions tomake approach to one another; a crosspiece-forming step of removing saidjig, and then forming said plurality of crosspieces at portions otherthan portions corresponding to said large number of pixels, of anoptical waveguide plate; and a second laminating step of laminating asurface of said actuator substrate formed with said pixel structures anda surface of said optical waveguide plate formed with said crosspieceswith each other.
 26. A method for producing a display device,comprising: a pixel-forming step of forming pixel structures onrespective actuator elements of an actuator substrate arranged with saidactuator elements of a number corresponding to a large number of pixels;a crosspiece-forming step of using a jig including, on one surface of aplate member, a large number of size-defining members formed to havesubstantially the same height as that of crosspieces to be formed onsaid actuator substrate to form said plurality of crosspieces atportions formed with no size-defining member, of a surface of said jigformed with said size-defining members, said portions being other thanportions corresponding to said large number of pixels; a firstlaminating step of laminating said surface of said jig formed with saidsize-defining members and said crosspieces and a surface of saidactuator substrate formed with said pixel structures with each other; apressurizing step of pressurizing said jig and said actuator substratein directions to make approach to one another; and a second laminatingstep of removing said jig to transfer said crosspieces to said actuatorsubstrate, and then laminating an optical waveguide plate on at leastsaid crosspieces on said actuator substrate.
 27. A method for producinga display device, comprising: a crosspiece-forming step of forming aplurality of crosspieces at portions other than actuator elements, of anactuator substrate arranged with said actuator elements of a numbercorresponding to a large number of pixels; a pixel-forming step offorming pixel structures on said respective actuator element of saidactuator substrate; a first laminating step of a jig including, on onesurface of a plate member, a large number of size-defining membersformed to have substantially the same height as that of said crosspiecesto be formed on said actuator substrate to laminate a surface of saidjig formed with said size-defining members and a surface of saidactuator substrate formed with said crosspieces and said pixelstructures with each other; a pressurizing step of pressurizing said jigand said actuator substrate in directions to make approach to oneanother; and a second laminating step of removing said jig, and thenlaminating an optical waveguide plate on at least said crosspieces onsaid actuator substrate.
 28. A method for producing a display device,comprising: a crosspiece-forming step of forming a plurality ofcrosspieces at portions other than actuator elements, of an actuatorsubstrate arranged with said actuator elements of a number correspondingto a large number of pixels; a pixel-forming step of using a jigincluding, on one surface of a plate member, a large number ofsize-defining members formed to have substantially the same height asthat of said crosspieces to be formed on said actuator substrate to formpixel structures at portions corresponding to said large number ofpixels, said portions being formed with no size-defining member, of asurface of said jig formed with said size-defining members; a firstlaminating step of laminating said surface of said jig formed with saidsize-defining members and said pixel structures and a surface of saidactuator substrate formed with said crosspieces with each other; apressurizing step of pressurizing said jig and said actuator substratein directions to make approach to one another; and a second laminatingstep of removing said jig to transfer said pixel structures to saidactuator substrate, and then laminating an optical waveguide plate on atleast said crosspieces on said actuator substrate.
 29. A method forproducing a display device, comprising: a crosspiece-forming step ofusing a jig including, on one surface of a plate member, a large numberof size-defining members formed to have substantially the same height asthat of crosspieces to be formed on an actuator substrate to form saidplurality of crosspieces at portions formed with no size-definingmember, of a surface of said jig formed with said size-defining members,said portions being other than portions corresponding to a large numberof pixels; a pixel-forming step of forming pixel structures at portionscorresponding to said large number of pixels, said portions being formedwith no size-defining member, of said surface of said jig formed withsaid size-defining members; a first laminating step of laminating saidactuator substrate arranged with actuator elements of a numbercorresponding to said large number of pixels on said crosspieces andsaid pixel structures on said jig; a pressurizing stop of pressurizingsaid jig and said actuator substrate in directions to make approach toone another; and a second laminating step of removing said jig totransfer said crosspieces and said pixel a to said at actuatorsubstrate, and then laminating an optical waveguide plate on at leastsaid crosspieces.
 30. The method for producing said display deviceaccording to claim 20, wherein when said crosspieces are formed, saidmembers for constructing said crosspieces are laminated by utilizingsurface tension of liquid.
 31. The method for producing said displaydevice according to claim 20, wherein said crosspiece-forming stepcomprises forming said crosspieces at said portions of said platemember, and then hardening said crosspieces.
 32. The method forproducing said display device according to claim 14, wherein saidpressurizing step comprises hardening at least said pixel structureswhile pressurizing said actuator substrate and said member to bepressurized together with said actuator substrate.
 33. The method forproducing said display device according to claim 14, wherein saidoptical waveguide plate includes a gap-forming layer at a portioncorresponding to said crosspiece.
 34. The method for producing saiddisplay device according to claim 14, wherein a gap-forming layer ispreviously formed on said crosspiece before laminating said opticalwaveguide plate.
 35. The method for producing said display deviceaccording to claim 14, wherein when said actuator substrate and saidmember to be pressurized together with said actuator substrate arepressurized, a preliminary treatment is performed for gap formation, anda predetermined gap is formed between said pixel structure and saidoptical waveguide plate during said hardening of at least said pixelstructures performed thereafter.
 36. The method for producing saiddisplay device according to claim 14, wherein a vacuum packaging methodis used to pressurize said actuator substrate and said member to bepressurized together with said actuator substrate.
 37. The method forproducing said display device according to claim 14, wherein a lowpressure press method is used to pressurize said actuator substrate andsaid member to be pressurized together with said actuator substrate. 38.The method for producing said display device according to claim 19,wherein: said plate member, which is used to be laminated on saidactuator substrate in said first laminating step, has a projection at aportion corresponding to each of said pixel structures; and a recesscorresponding to said projection is formed on said surface of said pixelstructure upon said pressurization performed in said pressurizing stepafter said first laminating step.
 39. The method for producing saiddisplay device according to claim 19, wherein: said plate member, whichis used to be laminated on said actuator substrate in said firstlaminating step, has a projection at a portion corresponding to each ofsaid pixel structures; and a step corresponding to said projection isformed on said surface of said pixel structure upon said pressurizationperformed in said pressurizing step after said first laminating step.40. The method for producing said display device according to claim 19,wherein: said plate member, which is used to be laminated on saidactuator substrate in said first laminating step, has a convexconfiguration formed at a portion corresponding to each of said pixelstructures; and a concave configuration corresponding to said convexconfiguration is formed on said surface of said pixel structure uponsaid pressurization performed in said pressurizing step after said firstlaminating step.